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http://rosettacode.org/wiki/Fixed_length_records
|
Fixed length records
|
Fixed length read/write
Before terminals, computers commonly used punch card readers or paper tape input.
A common format before these devices were superseded by terminal technology was based on the Hollerith code, Hollerith code.
These input devices handled 80 columns per card and had a limited character set, encoded by punching holes in one or more rows of the card for each column.
These devices assumed/demanded a fixed line width of 80 characters, newlines were not required (and could not even be encoded in some systems).
Task
Write a program to read 80 column fixed length records (no newline terminators (but newline characters allowed in the data)) and then write out the reverse of each line as fixed length 80 column records.
Samples here use printable characters, but that is not a given with fixed length data. Filenames used are sample.txt, infile.dat, outfile.dat.
Note: There are no newlines, inputs and outputs are fixed at 80 columns, no more, no less, space padded. Fixed length data is 8 bit complete. NUL bytes of zero are allowed.
These fixed length formats are still in wide use on mainframes, with JCL and with COBOL (which commonly use EBCDIC encoding and not ASCII). Most of the large players in day to day financial transactions know all about fixed length records and the expression logical record length.
Sample data
To create the sample input file, use an editor that supports fixed length records or use a conversion utility. For instance, most GNU/Linux versions of dd support blocking and unblocking records with a conversion byte size.
Line 1...1.........2.........3.........4.........5.........6.........7.........8
Line 2
Line 3
Line 4
Line 6
Line 7
Indented line 8............................................................
Line 9 RT MARGIN
prompt$ dd if=sample.txt of=infile.dat cbs=80 conv=block
prompt$ dd if=infile.dat cbs=80 conv=unblock
Bonus round
Forth systems often include BLOCK words. A block is 1024 bytes. Source code is stored as 16 lines of 64 characters each (again, no newline character or sequence to mark the end of a line).
Write a program to convert a block file to text (using newlines). Trailing spaces should be excluded from the output.
Also demonstrate how to convert from a normal text file to block form. All lines either truncated or padded to 64 characters with no newline terminators. The last block filled to be exactly 1024 characters by adding blanks if needed. Assume a full range of 8 bit byte values for each character.
The COBOL example uses forth.txt and forth.blk filenames.
|
#Ruby
|
Ruby
|
open("outfile.dat", "w") do |out_f|
open("infile.dat") do |in_f|
while record = in_f.read(80)
out_f << record.reverse
end
end
end # both files automatically closed
|
http://rosettacode.org/wiki/Floyd-Warshall_algorithm
|
Floyd-Warshall algorithm
|
The Floyd–Warshall algorithm is an algorithm for finding shortest paths in a weighted graph with positive or negative edge weights.
Task
Find the lengths of the shortest paths between all pairs of vertices of the given directed graph. Your code may assume that the input has already been checked for loops, parallel edges and negative cycles.
Print the pair, the distance and (optionally) the path.
Example
pair dist path
1 -> 2 -1 1 -> 3 -> 4 -> 2
1 -> 3 -2 1 -> 3
1 -> 4 0 1 -> 3 -> 4
2 -> 1 4 2 -> 1
2 -> 3 2 2 -> 1 -> 3
2 -> 4 4 2 -> 1 -> 3 -> 4
3 -> 1 5 3 -> 4 -> 2 -> 1
3 -> 2 1 3 -> 4 -> 2
3 -> 4 2 3 -> 4
4 -> 1 3 4 -> 2 -> 1
4 -> 2 -1 4 -> 2
4 -> 3 1 4 -> 2 -> 1 -> 3
See also
Floyd-Warshall Algorithm - step by step guide (youtube)
|
#Fortran
|
Fortran
|
module floyd_warshall_algorithm
use, intrinsic :: ieee_arithmetic
implicit none
integer, parameter :: floating_point_kind = &
& ieee_selected_real_kind (6, 37)
integer, parameter :: fpk = floating_point_kind
integer, parameter :: nil_vertex = 0
type :: edge
integer :: u
real(kind = fpk) :: weight
integer :: v
end type edge
type :: edge_list
type(edge), allocatable :: element(:)
end type edge_list
contains
subroutine make_example_graph (edges)
type(edge_list), intent(out) :: edges
allocate (edges%element(1:5))
edges%element(1) = edge (1, -2.0, 3)
edges%element(2) = edge (3, +2.0, 4)
edges%element(3) = edge (4, -1.0, 2)
edges%element(4) = edge (2, +4.0, 1)
edges%element(5) = edge (2, +3.0, 3)
end subroutine make_example_graph
function find_max_vertex (edges) result (n)
type(edge_list), intent(in) :: edges
integer n
integer i
n = 1
do i = lbound (edges%element, 1), ubound (edges%element, 1)
n = max (n, edges%element(i)%u)
n = max (n, edges%element(i)%v)
end do
end function find_max_vertex
subroutine floyd_warshall (edges, max_vertex, distance, next_vertex)
type(edge_list), intent(in) :: edges
integer, intent(out) :: max_vertex
real(kind = fpk), allocatable, intent(out) :: distance(:,:)
integer, allocatable, intent(out) :: next_vertex(:,:)
integer :: n
integer :: i, j, k
integer :: u, v
real(kind = fpk) :: dist_ikj
real(kind = fpk) :: infinity
n = find_max_vertex (edges)
max_vertex = n
allocate (distance(1:n, 1:n))
allocate (next_vertex(1:n, 1:n))
infinity = ieee_value (1.0_fpk, ieee_positive_inf)
! Initialize.
do i = 1, n
do j = 1, n
distance(i, j) = infinity
next_vertex (i, j) = nil_vertex
end do
end do
do i = lbound (edges%element, 1), ubound (edges%element, 1)
u = edges%element(i)%u
v = edges%element(i)%v
distance(u, v) = edges%element(i)%weight
next_vertex(u, v) = v
end do
do i = 1, n
distance(i, i) = 0.0_fpk ! Distance from a vertex to itself.
next_vertex(i, i) = i
end do
! Perform the algorithm.
do k = 1, n
do i = 1, n
do j = 1, n
dist_ikj = distance(i, k) + distance(k, j)
if (dist_ikj < distance(i, j)) then
distance(i, j) = dist_ikj
next_vertex(i, j) = next_vertex(i, k)
end if
end do
end do
end do
end subroutine floyd_warshall
subroutine print_path (next_vertex, u, v)
integer, intent(in) :: next_vertex(:,:)
integer, intent(in) :: u, v
integer i
if (next_vertex(u, v) /= nil_vertex) then
i = u
write (*, '(I0)', advance = 'no') i
do while (i /= v)
i = next_vertex(i, v)
write (*, '('' -> '', I0)', advance = 'no') i
end do
end if
end subroutine print_path
end module floyd_warshall_algorithm
program floyd_warshall_task
use, non_intrinsic :: floyd_warshall_algorithm
implicit none
type(edge_list) :: example_graph
integer :: max_vertex
real(kind = fpk), allocatable :: distance(:,:)
integer, allocatable :: next_vertex(:,:)
integer :: u, v
call make_example_graph (example_graph)
call floyd_warshall (example_graph, max_vertex, distance, &
& next_vertex)
1000 format (1X, I0, ' -> ', I0, 5X, F4.1, 6X)
write (*, '('' pair distance path'')')
write (*, '(''---------------------------------------'')')
do u = 1, max_vertex
do v = 1, max_vertex
if (u /= v) then
write (*, 1000, advance = 'no') u, v, distance(u, v)
call print_path (next_vertex, u, v)
write (*, '()', advance = 'yes')
end if
end do
end do
end program floyd_warshall_task
|
http://rosettacode.org/wiki/Function_definition
|
Function definition
|
A function is a body of code that returns a value.
The value returned may depend on arguments provided to the function.
Task
Write a definition of a function called "multiply" that takes two arguments and returns their product.
(Argument types should be chosen so as not to distract from showing how functions are created and values returned).
Related task
Function prototype
|
#PureBasic
|
PureBasic
|
Procedure multiply(a,b)
ProcedureReturn a*b
EndProcedure
|
http://rosettacode.org/wiki/Forward_difference
|
Forward difference
|
Task
Provide code that produces a list of numbers which is the nth order forward difference, given a non-negative integer (specifying the order) and a list of numbers.
The first-order forward difference of a list of numbers A is a new list B, where Bn = An+1 - An.
List B should have one fewer element as a result.
The second-order forward difference of A will be:
tdefmodule Diff do
def forward(arr,i\\1) do
forward(arr,[],i)
end
def forward([_|[]],diffs,i) do
if i == 1 do
IO.inspect diffs
else
forward(diffs,[],i-1)
end
end
def forward([val1|[val2|vals]],diffs,i) do
forward([val2|vals],diffs++[val2-val1],i)
end
end
The same as the first-order forward difference of B.
That new list will have two fewer elements than A and one less than B.
The goal of this task is to repeat this process up to the desired order.
For a more formal description, see the related Mathworld article.
Algorithmic options
Iterate through all previous forward differences and re-calculate a new array each time.
Use this formula (from Wikipedia):
Δ
n
[
f
]
(
x
)
=
∑
k
=
0
n
(
n
k
)
(
−
1
)
n
−
k
f
(
x
+
k
)
{\displaystyle \Delta ^{n}[f](x)=\sum _{k=0}^{n}{n \choose k}(-1)^{n-k}f(x+k)}
(Pascal's Triangle may be useful for this option.)
|
#JavaScript
|
JavaScript
|
(() => {
'use strict';
// forwardDifference :: Num a => [a] -> [a]
const forwardDifference = xs =>
zipWith(subtract)(xs)(tail(xs));
// nthForwardDifference :: Num a => [a] -> Int -> [a]
const nthForwardDifference = xs =>
index(iterate(forwardDifference)(xs)).Just;
//----------------------- TEST ------------------------
// main :: IO ()
const main = () =>
unlines(
take(10)(
iterate(forwardDifference)(
[90, 47, 58, 29, 22, 32, 55, 5, 55, 73]
)
).map((x, i) => justifyRight(2)('x')(i) + (
' -> '
) + JSON.stringify(x))
);
//----------------- GENERIC FUNCTIONS -----------------
// Just :: a -> Maybe a
const Just = x => ({
type: 'Maybe',
Nothing: false,
Just: x
});
// Nothing :: Maybe a
const Nothing = () => ({
type: 'Maybe',
Nothing: true,
});
// Tuple (,) :: a -> b -> (a, b)
const Tuple = a =>
b => ({
type: 'Tuple',
'0': a,
'1': b,
length: 2
});
// index (!!) :: [a] -> Int -> Maybe a
// index (!!) :: Generator (Int, a) -> Int -> Maybe a
// index (!!) :: String -> Int -> Maybe Char
const index = xs => i => {
const s = xs.constructor.constructor.name;
return 'GeneratorFunction' !== s ? (() => {
const v = xs[i];
return undefined !== v ? Just(v) : Nothing();
})() : Just(take(i)(xs), xs.next().value);
};
// iterate :: (a -> a) -> a -> Gen [a]
const iterate = f =>
function*(x) {
let v = x;
while (true) {
yield(v);
v = f(v);
}
};
// justifyRight :: Int -> Char -> String -> String
const justifyRight = n =>
// The string s, preceded by enough padding (with
// the character c) to reach the string length n.
c => s => n > s.length ? (
s.padStart(n, c)
) : s;
// length :: [a] -> Int
const length = xs =>
// Returns Infinity over objects without finite
// length. This enables zip and zipWith to choose
// the shorter argument when one is non-finite,
// like cycle, repeat etc
(Array.isArray(xs) || 'string' === typeof xs) ? (
xs.length
) : Infinity;
// map :: (a -> b) -> [a] -> [b]
const map = f =>
// The list obtained by applying f
// to each element of xs.
// (The image of xs under f).
xs => (
Array.isArray(xs) ? (
xs
) : xs.split('')
).map(f);
// subtract :: Num -> Num -> Num
const subtract = x =>
y => y - x;
// tail :: [a] -> [a]
const tail = xs =>
// A new list consisting of all
// items of xs except the first.
0 < xs.length ? xs.slice(1) : [];
// take :: Int -> [a] -> [a]
// take :: Int -> String -> String
const take = n =>
// The first n elements of a list,
// string of characters, or stream.
xs => 'GeneratorFunction' !== xs
.constructor.constructor.name ? (
xs.slice(0, n)
) : [].concat.apply([], Array.from({
length: n
}, () => {
const x = xs.next();
return x.done ? [] : [x.value];
}));
// unlines :: [String] -> String
const unlines = xs =>
// A single string formed by the intercalation
// of a list of strings with the newline character.
xs.join('\n');
// zipWith :: (a -> b -> c) -> [a] -> [b] -> [c]
const zipWith = f => xs => ys => {
const
lng = Math.min(length(xs), length(ys)),
[as, bs] = [xs, ys].map(take(lng));
return Array.from({
length: lng
}, (_, i) => f(as[i])(
bs[i]
));
};
// MAIN ---
return main();
})();
|
http://rosettacode.org/wiki/Hello_world/Text
|
Hello world/Text
|
Hello world/Text is part of Short Circuit's Console Program Basics selection.
Task
Display the string Hello world! on a text console.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello world/Newbie
Hello world/Newline omission
Hello world/Standard error
Hello world/Web server
|
#X86-64_Assembly
|
X86-64 Assembly
|
option casemap:none
if @Platform eq 1
option dllimport:<kernel32>
ExitProcess proto :dword
option dllimport:none
exit equ ExitProcess
endif
printf proto :qword, :vararg
exit proto :dword
.code
main proc
invoke printf, CSTR("Goodbye, World!",10)
invoke exit, 0
ret
main endp
end
|
http://rosettacode.org/wiki/Formatted_numeric_output
|
Formatted numeric output
|
Task
Express a number in decimal as a fixed-length string with leading zeros.
For example, the number 7.125 could be expressed as 00007.125.
|
#OCaml
|
OCaml
|
Printf.printf "%09.3f\n" 7.125
|
http://rosettacode.org/wiki/Formatted_numeric_output
|
Formatted numeric output
|
Task
Express a number in decimal as a fixed-length string with leading zeros.
For example, the number 7.125 could be expressed as 00007.125.
|
#OpenEdge.2FProgress
|
OpenEdge/Progress
|
MESSAGE
STRING( 7.125, "99999.999" )
VIEW-AS ALERT-BOX.
|
http://rosettacode.org/wiki/Four_bit_adder
|
Four bit adder
|
Task
"Simulate" a four-bit adder.
This design can be realized using four 1-bit full adders.
Each of these 1-bit full adders can be built with two half adders and an or gate. ;
Finally a half adder can be made using an xor gate and an and gate.
The xor gate can be made using two nots, two ands and one or.
Not, or and and, the only allowed "gates" for the task, can be "imitated" by using the bitwise operators of your language.
If there is not a bit type in your language, to be sure that the not does not "invert" all the other bits of the basic type (e.g. a byte) we are not interested in, you can use an extra nand (and then not) with the constant 1 on one input.
Instead of optimizing and reducing the number of gates used for the final 4-bit adder, build it in the most straightforward way, connecting the other "constructive blocks", in turn made of "simpler" and "smaller" ones.
Schematics of the "constructive blocks"
(Xor gate with ANDs, ORs and NOTs)
(A half adder)
(A full adder)
(A 4-bit adder)
Solutions should try to be as descriptive as possible, making it as easy as possible to identify "connections" between higher-order "blocks".
It is not mandatory to replicate the syntax of higher-order blocks in the atomic "gate" blocks, i.e. basic "gate" operations can be performed as usual bitwise operations, or they can be "wrapped" in a block in order to expose the same syntax of higher-order blocks, at implementers' choice.
To test the implementation, show the sum of two four-bit numbers (in binary).
|
#LabVIEW
|
LabVIEW
|
{def xor
{lambda {:a :b}
{or {and :a {not :b}} {and :b {not :a}}}}}
-> xor
{def halfAdder
{lambda {:a :b}
{cons {and :a :b} {xor :a :b}}}}
-> halfAdder
{def fullAdder
{lambda {:a :b :c}
{let { {:b :b}
{:ha1 {halfAdder :c :a}} }
{let { {:ha1 :ha1}
{:ha2 {halfAdder {cdr :ha1} :b}} }
{cons {or {car :ha1} {car :ha2}} {cdr :ha2}} }}}}
-> fullAdder
{def 4bitsAdder
{lambda {:a4 :a3 :a2 :a1 :b4 :b3 :b2 :b1}
{let { {:a4 :a4} {:a3 :a3} {:a2 :a2} {:b4 :b4} {:b3 :b3} {:b2 :b2}
{:fa1 {fullAdder :a1 :b1 false}} }
{let { {:a4 :a4} {:a3 :a3} {:b4 :b4} {:b3 :b3}
{:fa1 :fa1}
{:fa2 {fullAdder :a2 :b2 {car :fa1}}} }
{let { {:a4 :a4} {:b4 :b4}
{:fa1 :fa1} {:fa2 :fa2}
{:fa3 {fullAdder :a3 :b3 {car :fa2}}} }
{let { {:fa1 :fa1} {:fa2 :fa2} {:fa3 :fa3}
{:fa4 {fullAdder :a4 :b4 {car :fa3}}} }
{car :fa4} {cdr :fa4} {cdr :fa3} {cdr :fa2} {cdr :fa1}}}}}}}
-> 4bitsAdder
{def bin2bool
{lambda {:b}
{if {W.empty? {W.rest :b}}
then {= {W.first :b} 1}
else {= {W.first :b} 1} {bin2bool {W.rest :b}}}}}
-> bin2bool
{def bool2bin
{lambda {:b}
{if {S.empty? {S.rest :b}}
then {if {S.first :b} then 1 else 0}
else {if {S.first :b} then 1 else 0}{bool2bin {S.rest :b}}}}}
-> bool2bin
{def bin2dec
{def bin2dec.r
{lambda {:p :r}
{if {A.empty? :p}
then :r
else {bin2dec.r {A.rest :p} {+ {A.first :p} {* 2 :r}}}}}}
{lambda {:p} {bin2dec.r {A.split :p} 0}}}
-> bin2dec
{def add
{def numbers 0000 0001 0010 0011 0100 0101 0110 0111
1000 1001 1010 1011 1100 1101 1110 1111}
{lambda {:a :b}
{bin2dec
{bool2bin
{4bitsAdder {bin2bool {S.get :a {numbers}}}
{bin2bool {S.get :b {numbers}}}}}}}}
-> add
{table
{S.map {lambda {:i} {tr
{S.map {{lambda {:i :j} {td {add :i :j}}} :i}
{S.serie 0 15}}}}
{S.serie 0 15}}
}
->
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29
15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
|
http://rosettacode.org/wiki/Forest_fire
|
Forest fire
|
This page uses content from Wikipedia. The original article was at Forest-fire model. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Task
Implement the Drossel and Schwabl definition of the forest-fire model.
It is basically a 2D cellular automaton where each cell can be in three distinct states (empty, tree and burning) and evolves according to the following rules (as given by Wikipedia)
A burning cell turns into an empty cell
A tree will burn if at least one neighbor is burning
A tree ignites with probability f even if no neighbor is burning
An empty space fills with a tree with probability p
Neighborhood is the Moore neighborhood; boundary conditions are so that on the boundary the cells are always empty ("fixed" boundary condition).
At the beginning, populate the lattice with empty and tree cells according to a specific probability (e.g. a cell has the probability 0.5 to be a tree). Then, let the system evolve.
Task's requirements do not include graphical display or the ability to change parameters (probabilities p and f ) through a graphical or command line interface.
Related tasks
See Conway's Game of Life
See Wireworld.
|
#C.23
|
C#
|
using System;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Threading;
using System.Windows.Forms;
namespace ForestFire
{
class Program : Form
{
private static readonly Random rand = new Random();
private Bitmap img;
public Program(int w, int h, int f, int p)
{
Size = new Size(w, h);
StartPosition = FormStartPosition.CenterScreen;
Thread t = new Thread(() => fire(f, p));
t.Start();
FormClosing += (object sender, FormClosingEventArgs e) => { t.Abort(); t = null; };
}
private void fire(int f, int p)
{
int clientWidth = ClientRectangle.Width;
int clientHeight = ClientRectangle.Height;
int cellSize = 10;
img = new Bitmap(clientWidth, clientHeight);
Graphics g = Graphics.FromImage(img);
CellState[,] state = InitializeForestFire(clientWidth, clientHeight);
uint generation = 0;
do
{
g.FillRectangle(Brushes.White, 0, 0, img.Width, img.Height);
state = StepForestFire(state, f, p);
for (int y = 0; y < clientHeight - cellSize; y += cellSize)
{
for (int x = 0; x < clientWidth - cellSize; x += cellSize)
{
switch (state[y, x])
{
case CellState.Empty:
break;
case CellState.Tree:
g.FillRectangle(Brushes.DarkGreen, x, y, cellSize, cellSize);
break;
case CellState.Burning:
g.FillRectangle(Brushes.DarkRed, x, y, cellSize, cellSize);
break;
}
}
}
Thread.Sleep(500);
Invoke((MethodInvoker)Refresh);
} while (generation < uint.MaxValue);
g.Dispose();
}
private CellState[,] InitializeForestFire(int width, int height)
{
// Create our state array, initialize all indices as Empty, and return it.
var state = new CellState[height, width];
state.Initialize();
return state;
}
private enum CellState : byte
{
Empty = 0,
Tree = 1,
Burning = 2
}
private CellState[,] StepForestFire(CellState[,] state, int f, int p)
{
/* Clone our old state, so we can write to our new state
* without changing any values in the old state. */
var newState = (CellState[,])state.Clone();
int numRows = state.GetLength(0);
int numCols = state.GetLength(1);
for (int r = 1; r < numRows - 1; r++)
{
for (int c = 1; c < numCols - 1; c++)
{
/*
* Check the current cell.
*
* If it's empty, give it a 1/p chance of becoming a tree.
*
* If it's a tree, check to see if any neighbors are burning.
* If so, set the cell's state to burning, otherwise give it
* a 1/f chance of combusting.
*
* If it's burning, set it to empty.
*/
switch (state[r, c])
{
case CellState.Empty:
if (rand.Next(0, p) == 0)
newState[r, c] = CellState.Tree;
break;
case CellState.Tree:
if (NeighborHasState(state, r, c, CellState.Burning) || rand.Next(0, f) == 0)
newState[r, c] = CellState.Burning;
break;
case CellState.Burning:
newState[r, c] = CellState.Empty;
break;
}
}
}
return newState;
}
private bool NeighborHasState(CellState[,] state, int x, int y, CellState value)
{
// Check each cell within a 1 cell radius for the specified value.
for (int r = -1; r <= 1; r++)
{
for (int c = -1; c <= 1; c++)
{
if (r == 0 && c == 0)
continue;
if (state[x + r, y + c] == value)
return true;
}
}
return false;
}
protected override void OnPaint(PaintEventArgs e)
{
base.OnPaint(e);
e.Graphics.DrawImage(img, 0, 0);
}
[STAThread]
static void Main(string[] args)
{
Application.Run(new Program(w: 500, h: 500, f: 2, p: 5));
}
}
}
|
http://rosettacode.org/wiki/Flatten_a_list
|
Flatten a list
|
Task
Write a function to flatten the nesting in an arbitrary list of values.
Your program should work on the equivalent of this list:
[[1], 2, [[3, 4], 5], [[[]]], [[[6]]], 7, 8, []]
Where the correct result would be the list:
[1, 2, 3, 4, 5, 6, 7, 8]
Related task
Tree traversal
|
#AutoHotkey
|
AutoHotkey
|
list := object(1, object(1, 1), 2, 2, 3, object(1, object(1, 3, 2, 4)
, 2, 5), 4, object(1, object(1, object(1, object()))), 5
, object(1, object(1, 6)), 6, 7, 7, 8, 9, object())
msgbox % objPrint(list) ; (( 1 ) 2 (( 3 4 ) 5 )(((())))(( 6 )) 7 8 ())
msgbox % objPrint(objFlatten(list)) ; ( 1 2 3 4 5 6 7 8 )
return
!r::reload
!q::exitapp
objPrint(ast, reserved=0)
{
if !isobject(ast)
return " " ast " "
if !reserved
reserved := object("seen" . &ast, 1) ; to keep track of unique objects within top object
enum := ast._newenum()
while enum[key, value]
{
if reserved["seen" . &value]
continue ; don't copy repeat objects (circular references)
; string .= key . ": " . objPrint(value, reserved)
string .= objPrint(value, reserved)
}
return "(" string ")"
}
objFlatten(ast)
{
if !isobject(ast)
return ast
flat := object() ; flat object
enum := ast._newenum()
while enum[key, value]
{
if !isobject(value)
flat._Insert(value)
else
{
next := objFlatten(value)
loop % next._MaxIndex()
flat._Insert(next[A_Index])
}
}
return flat
}
|
http://rosettacode.org/wiki/Flipping_bits_game
|
Flipping bits game
|
The game
Given an N×N square array of zeroes or ones in an initial configuration, and a target configuration of zeroes and ones.
The game is to transform one to the other in as few moves as possible by inverting whole numbered rows or whole lettered
columns at once (as one move).
In an inversion. any 1 becomes 0, and any 0 becomes 1 for that whole row or column.
Task
Create a program to score for the Flipping bits game.
The game should create an original random target configuration and a starting configuration.
Ensure that the starting position is never the target position.
The target position must be guaranteed as reachable from the starting position. (One possible way to do this is to generate the start position by legal flips from a random target position. The flips will always be reversible back to the target from the given start position).
The number of moves taken so far should be shown.
Show an example of a short game here, on this page, for a 3×3 array of bits.
|
#D
|
D
|
import std.stdio, std.random, std.ascii, std.string, std.range,
std.algorithm, std.conv;
enum N = 3; // Board side.
static assert(N <= lowercase.length);
enum columnIDs = lowercase[0 .. N];
alias Board = ubyte[N][N];
void flipBits(ref Board board, in size_t count=1) {
foreach (immutable _; 0 .. count)
board[uniform(0, $)][uniform(0, $)] ^= 1;
}
void notRow(ref Board board, in size_t i) pure nothrow {
board[i][] ^= 1;
}
void notColumn(ref Board board, in size_t i) pure nothrow {
foreach (ref row; board)
row[i] ^= 1;
}
Board generateGameBoard(in ref Board target) {
// board is generated with many flips, to keep parity unchanged.
Board board = target;
while (board == target)
foreach (immutable _; 0 .. 2 * N)
[¬Row, ¬Column][uniform(0, 2)](board, uniform(0, N));
return board;
}
void show(in ref Board board, in string comment) {
comment.writeln;
writefln(" %-(%c %)", columnIDs);
foreach (immutable j, const row; board)
writefln(" %2d %-(%d %)", j + 1, row);
}
void main() {
"T prints the target, and Q exits.\n".writeln;
// Create target and flip some of its bits randomly.
Board target;
flipBits(target, uniform(0, N) + 1);
show(target, "Target configuration is:");
auto board = generateGameBoard(target);
immutable prompt = format(" 1-%d / %s-%s to flip, or T, Q: ",
N, columnIDs[0], columnIDs.back);
uint move = 1;
while (board != target) {
show(board, format("\nMove %d:", move));
prompt.write;
immutable ans = readln.strip;
if (ans.length == 1 && columnIDs.canFind(ans)) {
board.notColumn(columnIDs.countUntil(ans));
move++;
} else if (iota(1, N + 1).map!text.canFind(ans)) {
board.notRow(ans.to!uint - 1);
move++;
} else if (ans == "T") {
show(target, "Target configuration is:");
} else if (ans == "Q") {
return "Game stopped.".writeln;
} else
writefln(" Wrong input '%s'. Try again.\n", ans.take(9));
}
"\nWell done!".writeln;
}
|
http://rosettacode.org/wiki/First_power_of_2_that_has_leading_decimal_digits_of_12
|
First power of 2 that has leading decimal digits of 12
|
(This task is taken from a Project Euler problem.)
(All numbers herein are expressed in base ten.)
27 = 128 and 7 is
the first power of 2 whose leading decimal digits are 12.
The next power of 2 whose leading decimal digits
are 12 is 80,
280 = 1208925819614629174706176.
Define p(L,n) to be the nth-smallest
value of j such that the base ten representation
of 2j begins with the digits of L .
So p(12, 1) = 7 and
p(12, 2) = 80
You are also given that:
p(123, 45) = 12710
Task
find:
p(12, 1)
p(12, 2)
p(123, 45)
p(123, 12345)
p(123, 678910)
display the results here, on this page.
|
#ALGOL_68
|
ALGOL 68
|
# find values of p( L, n ) where p( L, n ) is the nth-smallest j such that #
# the decimal representation of 2^j starts with the digits of L #
BEGIN
# returns a string representation of n with commas #
PROC commatise = ( LONG INT n )STRING:
BEGIN
STRING result := "";
STRING unformatted = whole( n, 0 );
INT ch count := 0;
FOR c FROM UPB unformatted BY -1 TO LWB unformatted DO
IF ch count <= 2 THEN ch count +:= 1
ELSE ch count := 1; "," +=: result
FI;
unformatted[ c ] +=: result
OD;
result
END # commatise # ;
# returns p( prefix, occurance ) #
PROC p = ( INT prefix, INT occurance )LONG INT:
BEGIN
LONG INT quarter long max int = long max int OVER 4;
LONG INT p2 := 1;
INT count := 0;
INT power := 0;
WHILE count < occurance DO
power +:= 1;
p2 +:= p2;
LONG INT pre := p2;
WHILE pre > prefix DO
pre OVERAB 10
OD;
IF pre = prefix THEN
count +:= 1
FI;
IF p2 > quarter long max int THEN
p2 OVERAB 10 000
FI
OD;
power
END # p # ;
# prints p( prefix, occurance ) #
PROC print p = ( INT prefix, INT occurance )VOID:
print( ( "p(", whole( prefix, 0 ), ", ", whole( occurance, 0 ), ") = ", commatise( p( prefix, occurance ) ), newline ) );
# task test cases #
print p( 12, 1 );
print p( 12, 2 );
print p( 123, 45 );
print p( 123, 12345 );
print p( 123, 678910 )
END
|
http://rosettacode.org/wiki/First-class_functions/Use_numbers_analogously
|
First-class functions/Use numbers analogously
|
In First-class functions, a language is showing how its manipulation of functions is similar to its manipulation of other types.
This tasks aim is to compare and contrast a language's implementation of first class functions, with its normal handling of numbers.
Write a program to create an ordered collection of a mixture of literally typed and expressions producing a real number, together with another ordered collection of their multiplicative inverses. Try and use the following pseudo-code to generate the numbers for the ordered collections:
x = 2.0
xi = 0.5
y = 4.0
yi = 0.25
z = x + y
zi = 1.0 / ( x + y )
Create a function multiplier, that given two numbers as arguments returns a function that when called with one argument, returns the result of multiplying the two arguments to the call to multiplier that created it and the argument in the call:
new_function = multiplier(n1,n2)
# where new_function(m) returns the result of n1 * n2 * m
Applying the multiplier of a number and its inverse from the two ordered collections of numbers in pairs, show that the result in each case is one.
Compare and contrast the resultant program with the corresponding entry in First-class functions. They should be close.
To paraphrase the task description: Do what was done before, but with numbers rather than functions
|
#Axiom
|
Axiom
|
(x,xi,y,yi) := (2.0,0.5,4.0,0.25)
(z,zi) := (x+y,1/(x+y))
(numbers,invers) := ([x,y,z],[xi,yi,zi])
multiplier(a:Float,b:Float):(Float->Float) == (m +-> a*b*m)
[multiplier(number,inver) 0.5 for number in numbers for inver in invers]
|
http://rosettacode.org/wiki/First-class_functions/Use_numbers_analogously
|
First-class functions/Use numbers analogously
|
In First-class functions, a language is showing how its manipulation of functions is similar to its manipulation of other types.
This tasks aim is to compare and contrast a language's implementation of first class functions, with its normal handling of numbers.
Write a program to create an ordered collection of a mixture of literally typed and expressions producing a real number, together with another ordered collection of their multiplicative inverses. Try and use the following pseudo-code to generate the numbers for the ordered collections:
x = 2.0
xi = 0.5
y = 4.0
yi = 0.25
z = x + y
zi = 1.0 / ( x + y )
Create a function multiplier, that given two numbers as arguments returns a function that when called with one argument, returns the result of multiplying the two arguments to the call to multiplier that created it and the argument in the call:
new_function = multiplier(n1,n2)
# where new_function(m) returns the result of n1 * n2 * m
Applying the multiplier of a number and its inverse from the two ordered collections of numbers in pairs, show that the result in each case is one.
Compare and contrast the resultant program with the corresponding entry in First-class functions. They should be close.
To paraphrase the task description: Do what was done before, but with numbers rather than functions
|
#BBC_BASIC
|
BBC BASIC
|
REM Create some numeric variables:
x = 2 : xi = 1/2
y = 4 : yi = 0.25
z = x + y : zi = 1 / (x + y)
REM Create the collections (here structures are used):
DIM c{x, y, z}
DIM ci{x, y, z}
c.x = x : c.y = y : c.z = z
ci.x = xi : ci.y = yi : ci.z = zi
REM Create some multiplier functions:
multx = FNmultiplier(c.x, ci.x)
multy = FNmultiplier(c.y, ci.y)
multz = FNmultiplier(c.z, ci.z)
REM Test applying the compositions:
x = 1.234567 : PRINT x " ", FN(multx)(x)
x = 2.345678 : PRINT x " ", FN(multy)(x)
x = 3.456789 : PRINT x " ", FN(multz)(x)
END
DEF FNmultiplier(n1,n2)
LOCAL f$, p%
f$ = "(m)=" + STR$n1 + "*" + STR$n2 + "*m"
DIM p% LEN(f$) + 4
$(p%+4) = f$ : !p% = p%+4
= p%
|
http://rosettacode.org/wiki/Flow-control_structures
|
Flow-control structures
|
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
Document common flow-control structures.
One common example of a flow-control structure is the goto construct.
Note that Conditional Structures and Loop Structures have their own articles/categories.
Related tasks
Conditional Structures
Loop Structures
|
#Fortran
|
Fortran
|
...
ASSIGN 1101 to WHENCE !Remember my return point.
GO TO 1000 !Dive into a "subroutine"
1101 CONTINUE !Resume.
...
ASSIGN 1102 to WHENCE !Prepare for another invocation.
GO TO 1000 !Like GOSUB in BASIC.
1102 CONTINUE !Carry on.
...
Common code, far away.
1000 do something !This has all the context available.
GO TO WHENCE !Return whence I came.
|
http://rosettacode.org/wiki/Flow-control_structures
|
Flow-control structures
|
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
Document common flow-control structures.
One common example of a flow-control structure is the goto construct.
Note that Conditional Structures and Loop Structures have their own articles/categories.
Related tasks
Conditional Structures
Loop Structures
|
#FreeBASIC
|
FreeBASIC
|
'$lang: "qb"
Gosub subrutina
bucle:
Print "Bucle infinito"
Goto bucle
End
subrutina:
Print "En subrutina"
Sleep 100
Return
Sleep
|
http://rosettacode.org/wiki/Four_is_magic
|
Four is magic
|
Task
Write a subroutine, function, whatever it may be called in your language, that takes an integer number and returns an English text sequence starting with the English cardinal representation of that integer, the word 'is' and then the English cardinal representation of the count of characters that made up the first word, followed by a comma.
Continue the sequence by using the previous count word as the first word of the next phrase, append 'is' and the cardinal count of the letters in that word.
Continue until you reach four. Since four has four characters, finish by adding the words 'four is magic' and a period. All integers will eventually wind up at four.
For instance, suppose your are given the integer 3. Convert 3 to Three, add is , then the cardinal character count of three, or five, with a comma to separate if from the next phrase. Continue the sequence five is four, (five has four letters), and finally, four is magic.
Three is five, five is four, four is magic.
For reference, here are outputs for 0 through 9.
Zero is four, four is magic.
One is three, three is five, five is four, four is magic.
Two is three, three is five, five is four, four is magic.
Three is five, five is four, four is magic.
Four is magic.
Five is four, four is magic.
Six is three, three is five, five is four, four is magic.
Seven is five, five is four, four is magic.
Eight is five, five is four, four is magic.
Nine is four, four is magic.
Some task guidelines
You may assume the input will only contain integer numbers.
Cardinal numbers between 20 and 100 may use either hyphens or spaces as word separators but they must use a word separator. (23 is twenty three or twenty-three not twentythree.)
Cardinal number conversions should follow the English short scale. (billion is 1e9, trillion is 1e12, etc.)
Cardinal numbers should not include commas. (20140 is twenty thousand one hundred forty not twenty thousand, one hundred forty.)
When converted to a string, 100 should be one hundred, not a hundred or hundred, 1000 should be one thousand, not a thousand or thousand.
When converted to a string, there should be no and in the cardinal string. 130 should be one hundred thirty not one hundred and thirty.
When counting characters, count all of the characters in the cardinal number including spaces and hyphens. One hundred fifty-one should be 21 not 18.
The output should follow the format "N is K, K is M, M is ... four is magic." (unless the input is 4, in which case the output should simply be "four is magic.")
The output can either be the return value from the function, or be displayed from within the function.
You are encouraged, though not mandated to use proper sentence capitalization.
You may optionally support negative numbers. -7 is negative seven.
Show the output here for a small representative sample of values, at least 5 but no more than 25. You are free to choose which which numbers to use for output demonstration.
You can choose to use a library, (module, external routine, whatever) to do the cardinal conversions as long as the code is easily and freely available to the public.
If you roll your own, make the routine accept at minimum any integer from 0 up to 999999. If you use a pre-made library, support at least up to unsigned 64 bit integers. (or the largest integer supported in your language if it is less.)
Four is magic is a popular code-golf task. This is not code golf. Write legible, idiomatic and well formatted code.
Related tasks
Four is the number of_letters in the ...
Look-and-say sequence
Number names
Self-describing numbers
Summarize and say sequence
Spelling of ordinal numbers
De Bruijn sequences
|
#Raku
|
Raku
|
use Lingua::EN::Numbers; # Version 2.4.0 or higher
sub card ($n) { cardinal($n).subst(/','/, '', :g) }
sub magic (Int $int is copy) {
my $string;
loop {
$string ~= "{ card($int) } is ";
if $int = ($int == 4) ?? 0 !! card($int).chars {
$string ~= "{ card($int) }, "
} else {
$string ~= "magic.\n";
last
}
}
$string.tc
}
.&magic.say for 0, 4, 6, 11, 13, 75, 337, -164, 9876543209, 2**256;
|
http://rosettacode.org/wiki/Floyd%27s_triangle
|
Floyd's triangle
|
Floyd's triangle lists the natural numbers in a right triangle aligned to the left where
the first row is 1 (unity)
successive rows start towards the left with the next number followed by successive naturals listing one more number than the line above.
The first few lines of a Floyd triangle looks like this:
1
2 3
4 5 6
7 8 9 10
11 12 13 14 15
Task
Write a program to generate and display here the first n lines of a Floyd triangle.
(Use n=5 and n=14 rows).
Ensure that when displayed in a mono-space font, the numbers line up in vertical columns as shown and that only one space separates numbers of the last row.
|
#AutoHotkey
|
AutoHotkey
|
Floyds_triangle(row){
i = 0
loop %row%
{
n := A_Index
loop, %n%
{
m := n, j := i, i++
while (m<row)
j += m , m++
res .= spaces(StrLen(j+1)-StrLen(i) +(A_Index=1?0:1)) i
}
if (A_Index < row)
res .= "`r`n"
}
return res
}
Spaces(no){
loop, % no
res.=" "
return % res
}
|
http://rosettacode.org/wiki/Fixed_length_records
|
Fixed length records
|
Fixed length read/write
Before terminals, computers commonly used punch card readers or paper tape input.
A common format before these devices were superseded by terminal technology was based on the Hollerith code, Hollerith code.
These input devices handled 80 columns per card and had a limited character set, encoded by punching holes in one or more rows of the card for each column.
These devices assumed/demanded a fixed line width of 80 characters, newlines were not required (and could not even be encoded in some systems).
Task
Write a program to read 80 column fixed length records (no newline terminators (but newline characters allowed in the data)) and then write out the reverse of each line as fixed length 80 column records.
Samples here use printable characters, but that is not a given with fixed length data. Filenames used are sample.txt, infile.dat, outfile.dat.
Note: There are no newlines, inputs and outputs are fixed at 80 columns, no more, no less, space padded. Fixed length data is 8 bit complete. NUL bytes of zero are allowed.
These fixed length formats are still in wide use on mainframes, with JCL and with COBOL (which commonly use EBCDIC encoding and not ASCII). Most of the large players in day to day financial transactions know all about fixed length records and the expression logical record length.
Sample data
To create the sample input file, use an editor that supports fixed length records or use a conversion utility. For instance, most GNU/Linux versions of dd support blocking and unblocking records with a conversion byte size.
Line 1...1.........2.........3.........4.........5.........6.........7.........8
Line 2
Line 3
Line 4
Line 6
Line 7
Indented line 8............................................................
Line 9 RT MARGIN
prompt$ dd if=sample.txt of=infile.dat cbs=80 conv=block
prompt$ dd if=infile.dat cbs=80 conv=unblock
Bonus round
Forth systems often include BLOCK words. A block is 1024 bytes. Source code is stored as 16 lines of 64 characters each (again, no newline character or sequence to mark the end of a line).
Write a program to convert a block file to text (using newlines). Trailing spaces should be excluded from the output.
Also demonstrate how to convert from a normal text file to block form. All lines either truncated or padded to 64 characters with no newline terminators. The last block filled to be exactly 1024 characters by adding blanks if needed. Assume a full range of 8 bit byte values for each character.
The COBOL example uses forth.txt and forth.blk filenames.
|
#Rust
|
Rust
|
use std::fs::File;
use std::io::prelude::*;
use std::io::{BufReader, BufWriter};
fn reverse_file(
input_filename: &str,
output_filename: &str,
record_len: usize,
) -> std::io::Result<()> {
let mut input = BufReader::new(File::open(input_filename)?);
let mut output = BufWriter::new(File::create(output_filename)?);
let mut buffer = vec![0; record_len];
while input.read(&mut buffer)? == record_len {
buffer.reverse();
output.write_all(&buffer)?;
}
output.flush()?;
Ok(())
}
fn main() {
match reverse_file("infile.dat", "outfile.dat", 80) {
Ok(()) => {}
Err(error) => eprintln!("I/O error: {}", error),
}
}
|
http://rosettacode.org/wiki/Fixed_length_records
|
Fixed length records
|
Fixed length read/write
Before terminals, computers commonly used punch card readers or paper tape input.
A common format before these devices were superseded by terminal technology was based on the Hollerith code, Hollerith code.
These input devices handled 80 columns per card and had a limited character set, encoded by punching holes in one or more rows of the card for each column.
These devices assumed/demanded a fixed line width of 80 characters, newlines were not required (and could not even be encoded in some systems).
Task
Write a program to read 80 column fixed length records (no newline terminators (but newline characters allowed in the data)) and then write out the reverse of each line as fixed length 80 column records.
Samples here use printable characters, but that is not a given with fixed length data. Filenames used are sample.txt, infile.dat, outfile.dat.
Note: There are no newlines, inputs and outputs are fixed at 80 columns, no more, no less, space padded. Fixed length data is 8 bit complete. NUL bytes of zero are allowed.
These fixed length formats are still in wide use on mainframes, with JCL and with COBOL (which commonly use EBCDIC encoding and not ASCII). Most of the large players in day to day financial transactions know all about fixed length records and the expression logical record length.
Sample data
To create the sample input file, use an editor that supports fixed length records or use a conversion utility. For instance, most GNU/Linux versions of dd support blocking and unblocking records with a conversion byte size.
Line 1...1.........2.........3.........4.........5.........6.........7.........8
Line 2
Line 3
Line 4
Line 6
Line 7
Indented line 8............................................................
Line 9 RT MARGIN
prompt$ dd if=sample.txt of=infile.dat cbs=80 conv=block
prompt$ dd if=infile.dat cbs=80 conv=unblock
Bonus round
Forth systems often include BLOCK words. A block is 1024 bytes. Source code is stored as 16 lines of 64 characters each (again, no newline character or sequence to mark the end of a line).
Write a program to convert a block file to text (using newlines). Trailing spaces should be excluded from the output.
Also demonstrate how to convert from a normal text file to block form. All lines either truncated or padded to 64 characters with no newline terminators. The last block filled to be exactly 1024 characters by adding blanks if needed. Assume a full range of 8 bit byte values for each character.
The COBOL example uses forth.txt and forth.blk filenames.
|
#Tcl
|
Tcl
|
chan configure stdin -translation binary
chan configure stdout -translation binary
set lines [regexp -inline -all {.{80}} [read stdin]]
puts -nonewline [join [lmap line $lines {string reverse $line}] ""]
# More "traditional" way
# while {[set line [read stdin 80]] ne ""} {
# puts -nonewline [string reverse $line]
# }
|
http://rosettacode.org/wiki/Fixed_length_records
|
Fixed length records
|
Fixed length read/write
Before terminals, computers commonly used punch card readers or paper tape input.
A common format before these devices were superseded by terminal technology was based on the Hollerith code, Hollerith code.
These input devices handled 80 columns per card and had a limited character set, encoded by punching holes in one or more rows of the card for each column.
These devices assumed/demanded a fixed line width of 80 characters, newlines were not required (and could not even be encoded in some systems).
Task
Write a program to read 80 column fixed length records (no newline terminators (but newline characters allowed in the data)) and then write out the reverse of each line as fixed length 80 column records.
Samples here use printable characters, but that is not a given with fixed length data. Filenames used are sample.txt, infile.dat, outfile.dat.
Note: There are no newlines, inputs and outputs are fixed at 80 columns, no more, no less, space padded. Fixed length data is 8 bit complete. NUL bytes of zero are allowed.
These fixed length formats are still in wide use on mainframes, with JCL and with COBOL (which commonly use EBCDIC encoding and not ASCII). Most of the large players in day to day financial transactions know all about fixed length records and the expression logical record length.
Sample data
To create the sample input file, use an editor that supports fixed length records or use a conversion utility. For instance, most GNU/Linux versions of dd support blocking and unblocking records with a conversion byte size.
Line 1...1.........2.........3.........4.........5.........6.........7.........8
Line 2
Line 3
Line 4
Line 6
Line 7
Indented line 8............................................................
Line 9 RT MARGIN
prompt$ dd if=sample.txt of=infile.dat cbs=80 conv=block
prompt$ dd if=infile.dat cbs=80 conv=unblock
Bonus round
Forth systems often include BLOCK words. A block is 1024 bytes. Source code is stored as 16 lines of 64 characters each (again, no newline character or sequence to mark the end of a line).
Write a program to convert a block file to text (using newlines). Trailing spaces should be excluded from the output.
Also demonstrate how to convert from a normal text file to block form. All lines either truncated or padded to 64 characters with no newline terminators. The last block filled to be exactly 1024 characters by adding blanks if needed. Assume a full range of 8 bit byte values for each character.
The COBOL example uses forth.txt and forth.blk filenames.
|
#Wren
|
Wren
|
import "io" for File
import "/str" for Str
var records = File.read("infile.dat")
File.create("outfile.dat") { |f|
for (record in Str.chunks(records, 80)) {
record = record[-1..0]
f.writeBytes(record)
}
}
records = File.read("outfile.dat")
for (record in Str.chunks(records, 80)) System.print(record)
|
http://rosettacode.org/wiki/Floyd-Warshall_algorithm
|
Floyd-Warshall algorithm
|
The Floyd–Warshall algorithm is an algorithm for finding shortest paths in a weighted graph with positive or negative edge weights.
Task
Find the lengths of the shortest paths between all pairs of vertices of the given directed graph. Your code may assume that the input has already been checked for loops, parallel edges and negative cycles.
Print the pair, the distance and (optionally) the path.
Example
pair dist path
1 -> 2 -1 1 -> 3 -> 4 -> 2
1 -> 3 -2 1 -> 3
1 -> 4 0 1 -> 3 -> 4
2 -> 1 4 2 -> 1
2 -> 3 2 2 -> 1 -> 3
2 -> 4 4 2 -> 1 -> 3 -> 4
3 -> 1 5 3 -> 4 -> 2 -> 1
3 -> 2 1 3 -> 4 -> 2
3 -> 4 2 3 -> 4
4 -> 1 3 4 -> 2 -> 1
4 -> 2 -1 4 -> 2
4 -> 3 1 4 -> 2 -> 1 -> 3
See also
Floyd-Warshall Algorithm - step by step guide (youtube)
|
#FreeBASIC
|
FreeBASIC
|
' FB 1.05.0 Win64
Const POSITIVE_INFINITY As Double = 1.0/0.0
Sub printResult(dist(any, any) As Double, nxt(any, any) As Integer)
Dim As Integer u, v
Print("pair dist path")
For i As Integer = 0 To UBound(nxt, 1)
For j As Integer = 0 To UBound(nxt, 1)
If i <> j Then
u = i + 1
v = j + 1
Print Str(u); " -> "; Str(v); " "; dist(i, j); " "; Str(u);
Do
u = nxt(u - 1, v - 1)
Print " -> "; Str(u);
Loop While u <> v
Print
End If
Next j
Next i
End Sub
Sub floydWarshall(weights(Any, Any) As Integer, numVertices As Integer)
Dim dist(0 To numVertices - 1, 0 To numVertices - 1) As Double
For i As Integer = 0 To numVertices - 1
For j As Integer = 0 To numVertices - 1
dist(i, j) = POSITIVE_INFINITY
Next j
Next i
For x As Integer = 0 To UBound(weights, 1)
dist(weights(x, 0) - 1, weights(x, 1) - 1) = weights(x, 2)
Next x
Dim nxt(0 To numVertices - 1, 0 To numVertices - 1) As Integer
For i As Integer = 0 To numVertices - 1
For j As Integer = 0 To numVertices - 1
If i <> j Then nxt(i, j) = j + 1
Next j
Next i
For k As Integer = 0 To numVertices - 1
For i As Integer = 0 To numVertices - 1
For j As Integer = 0 To numVertices - 1
If (dist(i, k) + dist(k, j)) < dist(i, j) Then
dist(i, j) = dist(i, k) + dist(k, j)
nxt(i, j) = nxt(i, k)
End If
Next j
Next i
Next k
printResult(dist(), nxt())
End Sub
Dim weights(4, 2) As Integer = {{1, 3, -2}, {2, 1, 4}, {2, 3, 3}, {3, 4, 2}, {4, 2, -1}}
Dim numVertices As Integer = 4
floydWarshall(weights(), numVertices)
Print
Print "Press any key to quit"
Sleep
|
http://rosettacode.org/wiki/Function_definition
|
Function definition
|
A function is a body of code that returns a value.
The value returned may depend on arguments provided to the function.
Task
Write a definition of a function called "multiply" that takes two arguments and returns their product.
(Argument types should be chosen so as not to distract from showing how functions are created and values returned).
Related task
Function prototype
|
#Python
|
Python
|
def multiply(a, b):
return a * b
|
http://rosettacode.org/wiki/Function_definition
|
Function definition
|
A function is a body of code that returns a value.
The value returned may depend on arguments provided to the function.
Task
Write a definition of a function called "multiply" that takes two arguments and returns their product.
(Argument types should be chosen so as not to distract from showing how functions are created and values returned).
Related task
Function prototype
|
#Q
|
Q
|
multiply:{[a;b] a*b}
|
http://rosettacode.org/wiki/Forward_difference
|
Forward difference
|
Task
Provide code that produces a list of numbers which is the nth order forward difference, given a non-negative integer (specifying the order) and a list of numbers.
The first-order forward difference of a list of numbers A is a new list B, where Bn = An+1 - An.
List B should have one fewer element as a result.
The second-order forward difference of A will be:
tdefmodule Diff do
def forward(arr,i\\1) do
forward(arr,[],i)
end
def forward([_|[]],diffs,i) do
if i == 1 do
IO.inspect diffs
else
forward(diffs,[],i-1)
end
end
def forward([val1|[val2|vals]],diffs,i) do
forward([val2|vals],diffs++[val2-val1],i)
end
end
The same as the first-order forward difference of B.
That new list will have two fewer elements than A and one less than B.
The goal of this task is to repeat this process up to the desired order.
For a more formal description, see the related Mathworld article.
Algorithmic options
Iterate through all previous forward differences and re-calculate a new array each time.
Use this formula (from Wikipedia):
Δ
n
[
f
]
(
x
)
=
∑
k
=
0
n
(
n
k
)
(
−
1
)
n
−
k
f
(
x
+
k
)
{\displaystyle \Delta ^{n}[f](x)=\sum _{k=0}^{n}{n \choose k}(-1)^{n-k}f(x+k)}
(Pascal's Triangle may be useful for this option.)
|
#jq
|
jq
|
# If n is a non-negative number and if input is
# a (possibly empty) array of numbers,
# emit an array, even if the input list is too short:
def ndiff(n):
if n==0 then .
elif n == 1 then . as $in | [range(1;length) | $in[.] - $in[.-1]]
else ndiff(1) | ndiff(n-1)
end;
|
http://rosettacode.org/wiki/Forward_difference
|
Forward difference
|
Task
Provide code that produces a list of numbers which is the nth order forward difference, given a non-negative integer (specifying the order) and a list of numbers.
The first-order forward difference of a list of numbers A is a new list B, where Bn = An+1 - An.
List B should have one fewer element as a result.
The second-order forward difference of A will be:
tdefmodule Diff do
def forward(arr,i\\1) do
forward(arr,[],i)
end
def forward([_|[]],diffs,i) do
if i == 1 do
IO.inspect diffs
else
forward(diffs,[],i-1)
end
end
def forward([val1|[val2|vals]],diffs,i) do
forward([val2|vals],diffs++[val2-val1],i)
end
end
The same as the first-order forward difference of B.
That new list will have two fewer elements than A and one less than B.
The goal of this task is to repeat this process up to the desired order.
For a more formal description, see the related Mathworld article.
Algorithmic options
Iterate through all previous forward differences and re-calculate a new array each time.
Use this formula (from Wikipedia):
Δ
n
[
f
]
(
x
)
=
∑
k
=
0
n
(
n
k
)
(
−
1
)
n
−
k
f
(
x
+
k
)
{\displaystyle \Delta ^{n}[f](x)=\sum _{k=0}^{n}{n \choose k}(-1)^{n-k}f(x+k)}
(Pascal's Triangle may be useful for this option.)
|
#Julia
|
Julia
|
ndiff(A::Array, n::Integer) = n < 1 ? A : diff(ndiff(A, n-1))
s = [90, 47, 58, 29, 22, 32, 55, 5, 55, 73]
println.(collect(ndiff(s, i) for i in 0:9))
|
http://rosettacode.org/wiki/Hello_world/Text
|
Hello world/Text
|
Hello world/Text is part of Short Circuit's Console Program Basics selection.
Task
Display the string Hello world! on a text console.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello world/Newbie
Hello world/Newline omission
Hello world/Standard error
Hello world/Web server
|
#XBasic
|
XBasic
|
PROGRAM "hello"
VERSION "0.0003"
DECLARE FUNCTION Entry()
FUNCTION Entry()
PRINT "Hello World"
END FUNCTION
END PROGRAM
|
http://rosettacode.org/wiki/Formatted_numeric_output
|
Formatted numeric output
|
Task
Express a number in decimal as a fixed-length string with leading zeros.
For example, the number 7.125 could be expressed as 00007.125.
|
#Oz
|
Oz
|
declare
fun {PrintFloat X Prec}
{Property.put 'print.floatPrecision' Prec}
S = {Float.toString X}
in
{Append
for I in 1..Prec-{Length S}+1 collect:C do {C &0} end
S}
end
in
{System.showInfo {PrintFloat 7.125 8}}
|
http://rosettacode.org/wiki/Formatted_numeric_output
|
Formatted numeric output
|
Task
Express a number in decimal as a fixed-length string with leading zeros.
For example, the number 7.125 could be expressed as 00007.125.
|
#PARI.2FGP
|
PARI/GP
|
printf("%09.4f\n", Pi)
|
http://rosettacode.org/wiki/Four_bit_adder
|
Four bit adder
|
Task
"Simulate" a four-bit adder.
This design can be realized using four 1-bit full adders.
Each of these 1-bit full adders can be built with two half adders and an or gate. ;
Finally a half adder can be made using an xor gate and an and gate.
The xor gate can be made using two nots, two ands and one or.
Not, or and and, the only allowed "gates" for the task, can be "imitated" by using the bitwise operators of your language.
If there is not a bit type in your language, to be sure that the not does not "invert" all the other bits of the basic type (e.g. a byte) we are not interested in, you can use an extra nand (and then not) with the constant 1 on one input.
Instead of optimizing and reducing the number of gates used for the final 4-bit adder, build it in the most straightforward way, connecting the other "constructive blocks", in turn made of "simpler" and "smaller" ones.
Schematics of the "constructive blocks"
(Xor gate with ANDs, ORs and NOTs)
(A half adder)
(A full adder)
(A 4-bit adder)
Solutions should try to be as descriptive as possible, making it as easy as possible to identify "connections" between higher-order "blocks".
It is not mandatory to replicate the syntax of higher-order blocks in the atomic "gate" blocks, i.e. basic "gate" operations can be performed as usual bitwise operations, or they can be "wrapped" in a block in order to expose the same syntax of higher-order blocks, at implementers' choice.
To test the implementation, show the sum of two four-bit numbers (in binary).
|
#Lambdatalk
|
Lambdatalk
|
{def xor
{lambda {:a :b}
{or {and :a {not :b}} {and :b {not :a}}}}}
-> xor
{def halfAdder
{lambda {:a :b}
{cons {and :a :b} {xor :a :b}}}}
-> halfAdder
{def fullAdder
{lambda {:a :b :c}
{let { {:b :b}
{:ha1 {halfAdder :c :a}} }
{let { {:ha1 :ha1}
{:ha2 {halfAdder {cdr :ha1} :b}} }
{cons {or {car :ha1} {car :ha2}} {cdr :ha2}} }}}}
-> fullAdder
{def 4bitsAdder
{lambda {:a4 :a3 :a2 :a1 :b4 :b3 :b2 :b1}
{let { {:a4 :a4} {:a3 :a3} {:a2 :a2} {:b4 :b4} {:b3 :b3} {:b2 :b2}
{:fa1 {fullAdder :a1 :b1 false}} }
{let { {:a4 :a4} {:a3 :a3} {:b4 :b4} {:b3 :b3}
{:fa1 :fa1}
{:fa2 {fullAdder :a2 :b2 {car :fa1}}} }
{let { {:a4 :a4} {:b4 :b4}
{:fa1 :fa1} {:fa2 :fa2}
{:fa3 {fullAdder :a3 :b3 {car :fa2}}} }
{let { {:fa1 :fa1} {:fa2 :fa2} {:fa3 :fa3}
{:fa4 {fullAdder :a4 :b4 {car :fa3}}} }
{car :fa4} {cdr :fa4} {cdr :fa3} {cdr :fa2} {cdr :fa1}}}}}}}
-> 4bitsAdder
{def bin2bool
{lambda {:b}
{if {W.empty? {W.rest :b}}
then {= {W.first :b} 1}
else {= {W.first :b} 1} {bin2bool {W.rest :b}}}}}
-> bin2bool
{def bool2bin
{lambda {:b}
{if {S.empty? {S.rest :b}}
then {if {S.first :b} then 1 else 0}
else {if {S.first :b} then 1 else 0}{bool2bin {S.rest :b}}}}}
-> bool2bin
{def bin2dec
{def bin2dec.r
{lambda {:p :r}
{if {A.empty? :p}
then :r
else {bin2dec.r {A.rest :p} {+ {A.first :p} {* 2 :r}}}}}}
{lambda {:p} {bin2dec.r {A.split :p} 0}}}
-> bin2dec
{def add
{def numbers 0000 0001 0010 0011 0100 0101 0110 0111
1000 1001 1010 1011 1100 1101 1110 1111}
{lambda {:a :b}
{bin2dec
{bool2bin
{4bitsAdder {bin2bool {S.get :a {numbers}}}
{bin2bool {S.get :b {numbers}}}}}}}}
-> add
{table
{S.map {lambda {:i} {tr
{S.map {{lambda {:i :j} {td {add :i :j}}} :i}
{S.serie 0 15}}}}
{S.serie 0 15}}
}
->
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29
15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
|
http://rosettacode.org/wiki/Fivenum
|
Fivenum
|
Many big data or scientific programs use boxplots to show distributions of data. In addition, sometimes saving large arrays for boxplots can be impractical and use extreme amounts of RAM. It can be useful to save large arrays as arrays with five numbers to save memory.
For example, the R programming language implements Tukey's five-number summary as the fivenum function.
Task
Given an array of numbers, compute the five-number summary.
Note
While these five numbers can be used to draw a boxplot, statistical packages will typically need extra data.
Moreover, while there is a consensus about the "box" of the boxplot, there are variations among statistical packages for the whiskers.
|
#11l
|
11l
|
F fivenum(array)
V n = array.len
V x = sorted(array)
V n4 = floor((n + 3.0) / 2.0) / 2.0
V d = [1.0, n4, (n + 1) / 2, n + 1 - n4, Float(n)]
[Float] sum_array
L(e) 5
V fl = Int(floor(d[e] - 1))
V ce = Int(ceil(d[e] - 1))
sum_array.append(0.5 * (x[fl] + x[ce]))
R sum_array
V x = [0.14082834, 0.09748790, 1.73131507, 0.87636009, -1.95059594, 0.73438555, -0.03035726, 1.46675970,
-0.74621349, -0.72588772, 0.63905160, 0.61501527, -0.98983780, -1.00447874, -0.62759469, 0.66206163,
1.04312009, -0.10305385, 0.75775634, 0.32566578]
print(fivenum(x))
|
http://rosettacode.org/wiki/Forest_fire
|
Forest fire
|
This page uses content from Wikipedia. The original article was at Forest-fire model. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Task
Implement the Drossel and Schwabl definition of the forest-fire model.
It is basically a 2D cellular automaton where each cell can be in three distinct states (empty, tree and burning) and evolves according to the following rules (as given by Wikipedia)
A burning cell turns into an empty cell
A tree will burn if at least one neighbor is burning
A tree ignites with probability f even if no neighbor is burning
An empty space fills with a tree with probability p
Neighborhood is the Moore neighborhood; boundary conditions are so that on the boundary the cells are always empty ("fixed" boundary condition).
At the beginning, populate the lattice with empty and tree cells according to a specific probability (e.g. a cell has the probability 0.5 to be a tree). Then, let the system evolve.
Task's requirements do not include graphical display or the ability to change parameters (probabilities p and f ) through a graphical or command line interface.
Related tasks
See Conway's Game of Life
See Wireworld.
|
#C.2B.2B
|
C++
|
#include <windows.h>
#include <string>
//--------------------------------------------------------------------------------------------------
using namespace std;
//--------------------------------------------------------------------------------------------------
enum states { NONE, TREE, FIRE };
const int MAX_SIDE = 500;
//--------------------------------------------------------------------------------------------------
class myBitmap
{
public:
myBitmap() : pen( NULL ) {}
~myBitmap()
{
DeleteObject( pen );
DeleteDC( hdc );
DeleteObject( bmp );
}
bool create( int w, int h )
{
BITMAPINFO bi;
ZeroMemory( &bi, sizeof( bi ) );
bi.bmiHeader.biSize = sizeof( bi.bmiHeader );
bi.bmiHeader.biBitCount = sizeof( DWORD ) * 8;
bi.bmiHeader.biCompression = BI_RGB;
bi.bmiHeader.biPlanes = 1;
bi.bmiHeader.biWidth = w;
bi.bmiHeader.biHeight = -h;
HDC dc = GetDC( GetConsoleWindow() );
bmp = CreateDIBSection( dc, &bi, DIB_RGB_COLORS, &pBits, NULL, 0 );
if( !bmp ) return false;
hdc = CreateCompatibleDC( dc );
SelectObject( hdc, bmp );
ReleaseDC( GetConsoleWindow(), dc );
width = w; height = h;
return true;
}
void clear()
{
ZeroMemory( pBits, width * height * sizeof( DWORD ) );
}
void setPenColor( DWORD clr )
{
if( pen ) DeleteObject( pen );
pen = CreatePen( PS_SOLID, 1, clr );
SelectObject( hdc, pen );
}
void saveBitmap( string path )
{
BITMAPFILEHEADER fileheader;
BITMAPINFO infoheader;
BITMAP bitmap;
DWORD wb;
GetObject( bmp, sizeof( bitmap ), &bitmap );
DWORD* dwpBits = new DWORD[bitmap.bmWidth * bitmap.bmHeight];
ZeroMemory( dwpBits, bitmap.bmWidth * bitmap.bmHeight * sizeof( DWORD ) );
ZeroMemory( &infoheader, sizeof( BITMAPINFO ) );
ZeroMemory( &fileheader, sizeof( BITMAPFILEHEADER ) );
infoheader.bmiHeader.biBitCount = sizeof( DWORD ) * 8;
infoheader.bmiHeader.biCompression = BI_RGB;
infoheader.bmiHeader.biPlanes = 1;
infoheader.bmiHeader.biSize = sizeof( infoheader.bmiHeader );
infoheader.bmiHeader.biHeight = bitmap.bmHeight;
infoheader.bmiHeader.biWidth = bitmap.bmWidth;
infoheader.bmiHeader.biSizeImage = bitmap.bmWidth * bitmap.bmHeight * sizeof( DWORD );
fileheader.bfType = 0x4D42;
fileheader.bfOffBits = sizeof( infoheader.bmiHeader ) + sizeof( BITMAPFILEHEADER );
fileheader.bfSize = fileheader.bfOffBits + infoheader.bmiHeader.biSizeImage;
GetDIBits( hdc, bmp, 0, height, ( LPVOID )dwpBits, &infoheader, DIB_RGB_COLORS );
HANDLE file = CreateFile( path.c_str(), GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL );
WriteFile( file, &fileheader, sizeof( BITMAPFILEHEADER ), &wb, NULL );
WriteFile( file, &infoheader.bmiHeader, sizeof( infoheader.bmiHeader ), &wb, NULL );
WriteFile( file, dwpBits, bitmap.bmWidth * bitmap.bmHeight * 4, &wb, NULL );
CloseHandle( file );
delete [] dwpBits;
}
HDC getDC() const { return hdc; }
int getWidth() const { return width; }
int getHeight() const { return height; }
private:
HBITMAP bmp;
HDC hdc;
HPEN pen;
void *pBits;
int width, height;
};
//--------------------------------------------------------------------------------------------------
class forest
{
public:
forest()
{
_bmp.create( MAX_SIDE, MAX_SIDE );
initForest( 0.05f, 0.005f );
}
void initForest( float p, float f )
{
_p = p; _f = f;
seedForest();
}
void mainLoop()
{
display();
simulate();
}
void setHWND( HWND hwnd ) { _hwnd = hwnd; }
private:
float probRand() { return ( float )rand() / 32768.0f; }
void display()
{
HDC bdc = _bmp.getDC();
DWORD clr;
for( int y = 0; y < MAX_SIDE; y++ )
{
for( int x = 0; x < MAX_SIDE; x++ )
{
switch( _forest[x][y] )
{
case FIRE: clr = 255; break;
case TREE: clr = RGB( 0, 255, 0 ); break;
default: clr = 0;
}
SetPixel( bdc, x, y, clr );
}
}
HDC dc = GetDC( _hwnd );
BitBlt( dc, 0, 0, MAX_SIDE, MAX_SIDE, _bmp.getDC(), 0, 0, SRCCOPY );
ReleaseDC( _hwnd, dc );
}
void seedForest()
{
ZeroMemory( _forestT, sizeof( _forestT ) );
ZeroMemory( _forest, sizeof( _forest ) );
for( int y = 0; y < MAX_SIDE; y++ )
for( int x = 0; x < MAX_SIDE; x++ )
if( probRand() < _p ) _forest[x][y] = TREE;
}
bool getNeighbors( int x, int y )
{
int a, b;
for( int yy = -1; yy < 2; yy++ )
for( int xx = -1; xx < 2; xx++ )
{
if( !xx && !yy ) continue;
a = x + xx; b = y + yy;
if( a < MAX_SIDE && b < MAX_SIDE && a > -1 && b > -1 )
if( _forest[a][b] == FIRE ) return true;
}
return false;
}
void simulate()
{
for( int y = 0; y < MAX_SIDE; y++ )
{
for( int x = 0; x < MAX_SIDE; x++ )
{
switch( _forest[x][y] )
{
case FIRE: _forestT[x][y] = NONE; break;
case NONE: if( probRand() < _p ) _forestT[x][y] = TREE; break;
case TREE: if( getNeighbors( x, y ) || probRand() < _f ) _forestT[x][y] = FIRE;
}
}
}
for( int y = 0; y < MAX_SIDE; y++ )
for( int x = 0; x < MAX_SIDE; x++ )
_forest[x][y] = _forestT[x][y];
}
myBitmap _bmp;
HWND _hwnd;
BYTE _forest[MAX_SIDE][MAX_SIDE], _forestT[MAX_SIDE][MAX_SIDE];
float _p, _f;
};
//--------------------------------------------------------------------------------------------------
class wnd
{
public:
int wnd::Run( HINSTANCE hInst )
{
_hInst = hInst;
_hwnd = InitAll();
_ff.setHWND( _hwnd );
_ff.initForest( 0.02f, 0.001f );
ShowWindow( _hwnd, SW_SHOW );
UpdateWindow( _hwnd );
MSG msg;
ZeroMemory( &msg, sizeof( msg ) );
while( msg.message != WM_QUIT )
{
if( PeekMessage( &msg, NULL, 0, 0, PM_REMOVE ) != 0 )
{
TranslateMessage( &msg );
DispatchMessage( &msg );
}
else
{
_ff.mainLoop();
}
}
return UnregisterClass( "_FOREST_FIRE_", _hInst );
}
private:
static int WINAPI wnd::WndProc( HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam )
{
switch( msg )
{
case WM_DESTROY: PostQuitMessage( 0 ); break;
default:
return DefWindowProc( hWnd, msg, wParam, lParam );
}
return 0;
}
HWND InitAll()
{
WNDCLASSEX wcex;
ZeroMemory( &wcex, sizeof( wcex ) );
wcex.cbSize = sizeof( WNDCLASSEX );
wcex.style = CS_HREDRAW | CS_VREDRAW;
wcex.lpfnWndProc = ( WNDPROC )WndProc;
wcex.hInstance = _hInst;
wcex.hCursor = LoadCursor( NULL, IDC_ARROW );
wcex.hbrBackground = ( HBRUSH )( COLOR_WINDOW + 1 );
wcex.lpszClassName = "_FOREST_FIRE_";
RegisterClassEx( &wcex );
return CreateWindow( "_FOREST_FIRE_", ".: Forest Fire -- PJorente :.", WS_SYSMENU, CW_USEDEFAULT, 0, MAX_SIDE, MAX_SIDE, NULL, NULL, _hInst, NULL );
}
HINSTANCE _hInst;
HWND _hwnd;
forest _ff;
};
//--------------------------------------------------------------------------------------------------
int APIENTRY _tWinMain( HINSTANCE hInstance, HINSTANCE hPrevInstance, LPTSTR lpCmdLine, int nCmdShow )
{
srand( GetTickCount() );
wnd myWnd;
return myWnd.Run( hInstance );
}
//--------------------------------------------------------------------------------------------------
|
http://rosettacode.org/wiki/Flatten_a_list
|
Flatten a list
|
Task
Write a function to flatten the nesting in an arbitrary list of values.
Your program should work on the equivalent of this list:
[[1], 2, [[3, 4], 5], [[[]]], [[[6]]], 7, 8, []]
Where the correct result would be the list:
[1, 2, 3, 4, 5, 6, 7, 8]
Related task
Tree traversal
|
#BaCon
|
BaCon
|
OPTION COLLAPSE TRUE
lst$ = "\"1\",2,\"\\\"3,4\\\",5\",\"\\\"\\\\\"\\\\\"\\\"\",\"\\\"\\\\\"6\\\\\"\\\"\",7,8,\"\""
PRINT lst$
REPEAT
lst$ = FLATTEN$(lst$)
UNTIL AMOUNT(lst$, ",") = AMOUNT(FLATTEN$(lst$), ",")
PRINT SORT$(lst$, ",")
|
http://rosettacode.org/wiki/Flipping_bits_game
|
Flipping bits game
|
The game
Given an N×N square array of zeroes or ones in an initial configuration, and a target configuration of zeroes and ones.
The game is to transform one to the other in as few moves as possible by inverting whole numbered rows or whole lettered
columns at once (as one move).
In an inversion. any 1 becomes 0, and any 0 becomes 1 for that whole row or column.
Task
Create a program to score for the Flipping bits game.
The game should create an original random target configuration and a starting configuration.
Ensure that the starting position is never the target position.
The target position must be guaranteed as reachable from the starting position. (One possible way to do this is to generate the start position by legal flips from a random target position. The flips will always be reversible back to the target from the given start position).
The number of moves taken so far should be shown.
Show an example of a short game here, on this page, for a 3×3 array of bits.
|
#Elixir
|
Elixir
|
defmodule Flip_game do
@az Enum.map(?a..?z, &List.to_string([&1]))
@in2i Enum.concat(Enum.map(1..26, fn i -> {to_string(i), i} end),
Enum.with_index(@az) |> Enum.map(fn {c,i} -> {c,-i-1} end))
|> Enum.into(Map.new)
def play(n) when n>2 do
target = generate_target(n)
display(n, "Target: ", target)
board = starting_config(n, target)
play(n, target, board, 1)
end
def play(n, target, board, moves) do
display(n, "Board: ", board)
ans = IO.gets("row/column to flip: ") |> String.strip |> String.downcase
new_board = case @in2i[ans] do
i when i in 1..n -> flip_row(n, board, i)
i when i in -1..-n -> flip_column(n, board, -i)
_ -> IO.puts "invalid input: #{ans}"
board
end
if target == new_board do
display(n, "Board: ", new_board)
IO.puts "You solved the game in #{moves} moves"
else
IO.puts ""
play(n, target, new_board, moves+1)
end
end
defp generate_target(n) do
for i <- 1..n, j <- 1..n, into: Map.new, do: {{i, j}, :rand.uniform(2)-1}
end
defp starting_config(n, target) do
Enum.concat(1..n, -1..-n)
|> Enum.take_random(n)
|> Enum.reduce(target, fn x,acc ->
if x>0, do: flip_row(n, acc, x),
else: flip_column(n, acc, -x)
end)
end
defp flip_row(n, board, row) do
Enum.reduce(1..n, board, fn col,acc ->
Map.update!(acc, {row,col}, fn bit -> 1 - bit end)
end)
end
defp flip_column(n, board, col) do
Enum.reduce(1..n, board, fn row,acc ->
Map.update!(acc, {row,col}, fn bit -> 1 - bit end)
end)
end
defp display(n, title, board) do
IO.puts title
IO.puts " #{Enum.join(Enum.take(@az,n), " ")}"
Enum.each(1..n, fn row ->
:io.fwrite "~2w ", [row]
IO.puts Enum.map_join(1..n, " ", fn col -> board[{row, col}] end)
end)
end
end
Flip_game.play(3)
|
http://rosettacode.org/wiki/Flipping_bits_game
|
Flipping bits game
|
The game
Given an N×N square array of zeroes or ones in an initial configuration, and a target configuration of zeroes and ones.
The game is to transform one to the other in as few moves as possible by inverting whole numbered rows or whole lettered
columns at once (as one move).
In an inversion. any 1 becomes 0, and any 0 becomes 1 for that whole row or column.
Task
Create a program to score for the Flipping bits game.
The game should create an original random target configuration and a starting configuration.
Ensure that the starting position is never the target position.
The target position must be guaranteed as reachable from the starting position. (One possible way to do this is to generate the start position by legal flips from a random target position. The flips will always be reversible back to the target from the given start position).
The number of moves taken so far should be shown.
Show an example of a short game here, on this page, for a 3×3 array of bits.
|
#FOCAL
|
FOCAL
|
01.10 T "FLIP THE BITS"!"-------------"!!;S M=0
01.20 A "SIZE",N;I (N-2)1.2;I (8-N)1.2
01.30 F I=0,N*N-1;D 3.2;S G(I)=A;S B(I)=A
01.35 D 3.3;S L=FITR(A*5)*2+6;F K=0,L;D 3.1;S Z=A;D 3.2;D 4.4
01.40 S A=0;F I=0,N*N-1;S A=A+FABS(G(I)-B(I))
01.42 T "MOVES",%3,M,!;S M=M+1
01.45 I (0-A)1.5;T !"YOU WIN!"!;Q
01.50 D 2
01.55 A "FLIP ROW (A) OR COLUMN (B)",A;S A=A-1;I (1-A)1.5
01.60 A "WHICH",Z;S Z=Z-1;I (N-A)1.6
01.65 D 4.4;G 1.4
02.10 T "--BOARD--";F A=1,N*2-5;T " "
02.14 T "--GOAL--"!" ";F A=0,N-1;T " ";D 5
02.15 T " ";F A=0,N-1;T " ";D 5
02.20 F R=0,N-1;S A=R;T !;D 2.4;T " ";D 2.5
02.30 T !!;R
02.40 D 5;F C=0,N-1;D 2.6
02.50 D 5;F C=0,N-1;D 2.7
02.60 I (B(R*N+C)-1)2.8;T " 1"
02.70 I (G(R*N+C)-1)2.8;T " 1"
02.80 T " 0"
03.10 D 3.3;S A=FITR(A*N)
03.20 D 3.3;S A=FITR(A+0.5)
03.30 S A=FABS(FRAN())*10;S A=A-FITR(A)
04.40 I (A-1)4.5,4.6
04.50 F I=0,N-1;S B(Z*N+I)=1-B(Z*N+I)
04.60 F I=0,N-1;S B(I*N+Z)=1-B(I*N+Z)
05.10 I (A-7)5.2;T "H";R
05.20 I (A-6)5.3;T "G";R
05.30 I (A-5)5.4;T "F";R
05.40 I (A-4)5.5;T "E";R
05.50 I (A-3)5.6;T "D";R
05.60 I (A-2)5.7;T "C";R
05.70 I (A-1)5.8;T "B";R
05.80 T "A"
|
http://rosettacode.org/wiki/First_power_of_2_that_has_leading_decimal_digits_of_12
|
First power of 2 that has leading decimal digits of 12
|
(This task is taken from a Project Euler problem.)
(All numbers herein are expressed in base ten.)
27 = 128 and 7 is
the first power of 2 whose leading decimal digits are 12.
The next power of 2 whose leading decimal digits
are 12 is 80,
280 = 1208925819614629174706176.
Define p(L,n) to be the nth-smallest
value of j such that the base ten representation
of 2j begins with the digits of L .
So p(12, 1) = 7 and
p(12, 2) = 80
You are also given that:
p(123, 45) = 12710
Task
find:
p(12, 1)
p(12, 2)
p(123, 45)
p(123, 12345)
p(123, 678910)
display the results here, on this page.
|
#BASIC256
|
BASIC256
|
global FAC
FAC = 0.30102999566398119521373889472449302677
print p(12, 1)
print p(12, 2)
print p(123, 45)
print p(123, 12345)
print p(123, 678910)
end
function p(L, n)
cont = 0 : j = 0
LS = string(L)
while cont < n
j += 1
x = FAC * j
if x < length(LS) then continue while
y = 10^(x-int(x))
y *= 10^length(LS)
digits = string(y)
if left(digits,length(LS)) = LS then cont += 1
end while
return j
end function
|
http://rosettacode.org/wiki/First_power_of_2_that_has_leading_decimal_digits_of_12
|
First power of 2 that has leading decimal digits of 12
|
(This task is taken from a Project Euler problem.)
(All numbers herein are expressed in base ten.)
27 = 128 and 7 is
the first power of 2 whose leading decimal digits are 12.
The next power of 2 whose leading decimal digits
are 12 is 80,
280 = 1208925819614629174706176.
Define p(L,n) to be the nth-smallest
value of j such that the base ten representation
of 2j begins with the digits of L .
So p(12, 1) = 7 and
p(12, 2) = 80
You are also given that:
p(123, 45) = 12710
Task
find:
p(12, 1)
p(12, 2)
p(123, 45)
p(123, 12345)
p(123, 678910)
display the results here, on this page.
|
#C
|
C
|
#include <math.h>
#include <stdio.h>
int p(int l, int n) {
int test = 0;
double logv = log(2.0) / log(10.0);
int factor = 1;
int loop = l;
while (loop > 10) {
factor *= 10;
loop /= 10;
}
while (n > 0) {
int val;
test++;
val = (int)(factor * pow(10.0, fmod(test * logv, 1)));
if (val == l) {
n--;
}
}
return test;
}
void runTest(int l, int n) {
printf("p(%d, %d) = %d\n", l, n, p(l, n));
}
int main() {
runTest(12, 1);
runTest(12, 2);
runTest(123, 45);
runTest(123, 12345);
runTest(123, 678910);
return 0;
}
|
http://rosettacode.org/wiki/First-class_functions/Use_numbers_analogously
|
First-class functions/Use numbers analogously
|
In First-class functions, a language is showing how its manipulation of functions is similar to its manipulation of other types.
This tasks aim is to compare and contrast a language's implementation of first class functions, with its normal handling of numbers.
Write a program to create an ordered collection of a mixture of literally typed and expressions producing a real number, together with another ordered collection of their multiplicative inverses. Try and use the following pseudo-code to generate the numbers for the ordered collections:
x = 2.0
xi = 0.5
y = 4.0
yi = 0.25
z = x + y
zi = 1.0 / ( x + y )
Create a function multiplier, that given two numbers as arguments returns a function that when called with one argument, returns the result of multiplying the two arguments to the call to multiplier that created it and the argument in the call:
new_function = multiplier(n1,n2)
# where new_function(m) returns the result of n1 * n2 * m
Applying the multiplier of a number and its inverse from the two ordered collections of numbers in pairs, show that the result in each case is one.
Compare and contrast the resultant program with the corresponding entry in First-class functions. They should be close.
To paraphrase the task description: Do what was done before, but with numbers rather than functions
|
#C.23
|
C#
|
using System;
using System.Linq;
class Program
{
static void Main(string[] args)
{
double x, xi, y, yi, z, zi;
x = 2.0;
xi = 0.5;
y = 4.0;
yi = 0.25;
z = x + y;
zi = 1.0 / (x + y);
var numlist = new[] { x, y, z };
var numlisti = new[] { xi, yi, zi };
var multiplied = numlist.Zip(numlisti, (n1, n2) =>
{
Func<double, double> multiplier = m => n1 * n2 * m;
return multiplier;
});
foreach (var multiplier in multiplied)
Console.WriteLine(multiplier(0.5));
}
}
|
http://rosettacode.org/wiki/Flow-control_structures
|
Flow-control structures
|
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
Document common flow-control structures.
One common example of a flow-control structure is the goto construct.
Note that Conditional Structures and Loop Structures have their own articles/categories.
Related tasks
Conditional Structures
Loop Structures
|
#Gambas
|
Gambas
|
Public Sub Main()
Dim siCount As Short
LOOPIT:
Print siCount;;
Inc siCount
If siCount > 100 Then Quit
Goto LoopIt
End
|
http://rosettacode.org/wiki/Flow-control_structures
|
Flow-control structures
|
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
Document common flow-control structures.
One common example of a flow-control structure is the goto construct.
Note that Conditional Structures and Loop Structures have their own articles/categories.
Related tasks
Conditional Structures
Loop Structures
|
#Go
|
Go
|
func main() {
inf:
goto inf
}
|
http://rosettacode.org/wiki/Four_is_magic
|
Four is magic
|
Task
Write a subroutine, function, whatever it may be called in your language, that takes an integer number and returns an English text sequence starting with the English cardinal representation of that integer, the word 'is' and then the English cardinal representation of the count of characters that made up the first word, followed by a comma.
Continue the sequence by using the previous count word as the first word of the next phrase, append 'is' and the cardinal count of the letters in that word.
Continue until you reach four. Since four has four characters, finish by adding the words 'four is magic' and a period. All integers will eventually wind up at four.
For instance, suppose your are given the integer 3. Convert 3 to Three, add is , then the cardinal character count of three, or five, with a comma to separate if from the next phrase. Continue the sequence five is four, (five has four letters), and finally, four is magic.
Three is five, five is four, four is magic.
For reference, here are outputs for 0 through 9.
Zero is four, four is magic.
One is three, three is five, five is four, four is magic.
Two is three, three is five, five is four, four is magic.
Three is five, five is four, four is magic.
Four is magic.
Five is four, four is magic.
Six is three, three is five, five is four, four is magic.
Seven is five, five is four, four is magic.
Eight is five, five is four, four is magic.
Nine is four, four is magic.
Some task guidelines
You may assume the input will only contain integer numbers.
Cardinal numbers between 20 and 100 may use either hyphens or spaces as word separators but they must use a word separator. (23 is twenty three or twenty-three not twentythree.)
Cardinal number conversions should follow the English short scale. (billion is 1e9, trillion is 1e12, etc.)
Cardinal numbers should not include commas. (20140 is twenty thousand one hundred forty not twenty thousand, one hundred forty.)
When converted to a string, 100 should be one hundred, not a hundred or hundred, 1000 should be one thousand, not a thousand or thousand.
When converted to a string, there should be no and in the cardinal string. 130 should be one hundred thirty not one hundred and thirty.
When counting characters, count all of the characters in the cardinal number including spaces and hyphens. One hundred fifty-one should be 21 not 18.
The output should follow the format "N is K, K is M, M is ... four is magic." (unless the input is 4, in which case the output should simply be "four is magic.")
The output can either be the return value from the function, or be displayed from within the function.
You are encouraged, though not mandated to use proper sentence capitalization.
You may optionally support negative numbers. -7 is negative seven.
Show the output here for a small representative sample of values, at least 5 but no more than 25. You are free to choose which which numbers to use for output demonstration.
You can choose to use a library, (module, external routine, whatever) to do the cardinal conversions as long as the code is easily and freely available to the public.
If you roll your own, make the routine accept at minimum any integer from 0 up to 999999. If you use a pre-made library, support at least up to unsigned 64 bit integers. (or the largest integer supported in your language if it is less.)
Four is magic is a popular code-golf task. This is not code golf. Write legible, idiomatic and well formatted code.
Related tasks
Four is the number of_letters in the ...
Look-and-say sequence
Number names
Self-describing numbers
Summarize and say sequence
Spelling of ordinal numbers
De Bruijn sequences
|
#REXX
|
REXX
|
/*REXX pgm converts a # to English into the phrase: a is b, b is c, ... four is magic. */
numeric digits 3003 /*be able to handle gihugic numbers. */
parse arg x /*obtain optional numbers from the C.L.*/
if x='' then x= -164 0 4 6 11 13 75 100 337 9223372036854775807 /*use these defaults?*/
@.= . /*stemmed array used for memoization. */
do j=1 for words(x) /*process each of the numbers in list. */
say 4_is( word(x, j) ) /*display phrase that'll be returned. */
say /*display a blank line between outputs.*/
end /*j*/
exit /*stick a fork in it, we're all done. */
/*──────────────────────────────────────────────────────────────────────────────────────*/
4_is: procedure expose @.; parse arg #,,$ /*obtain the start number.*/
if #\==4 then do until L==4 /*Not 4? Process number.*/
@.#= $spell#(# 'quiet minus negative') /*spell number in English.*/
#= @.#; L= length(#) /*get the length of spelt#*/
if @.L==. then @.L= $spell#(L 'quiet') /*¬spelt before? Spell it.*/
$= $ # "is" @.L',' /*add phrase to the answer*/
#= L /*use the new number, ··· */
end /*until*/ /* ··· which will be spelt*/
$= strip($ 'four is magic.') /*finish the sentence with the finale. */
parse var $ first 2 other; upper first /*capitalize the first letter of output*/
return first || other /*return the sentence to the invoker. */
|
http://rosettacode.org/wiki/Floyd%27s_triangle
|
Floyd's triangle
|
Floyd's triangle lists the natural numbers in a right triangle aligned to the left where
the first row is 1 (unity)
successive rows start towards the left with the next number followed by successive naturals listing one more number than the line above.
The first few lines of a Floyd triangle looks like this:
1
2 3
4 5 6
7 8 9 10
11 12 13 14 15
Task
Write a program to generate and display here the first n lines of a Floyd triangle.
(Use n=5 and n=14 rows).
Ensure that when displayed in a mono-space font, the numbers line up in vertical columns as shown and that only one space separates numbers of the last row.
|
#AWK
|
AWK
|
#!/bin/awk -f
BEGIN {
if (rows !~ /^[0-9]+$/ || rows < 0) {
print "invalid rows or missing from command line"
print "syntax: awk -v rows=14 -f floyds_triangle.awk"
exit 1
}
for (row=cols=1; row<=rows; row++ cols++) {
width[row] = length(row + (rows * (rows-1))/2)
for (col=1; col<=cols; col++)
printf("%*d%c", width[col], ++n, row == col ? "\n" : " ")
}
}
|
http://rosettacode.org/wiki/Fixed_length_records
|
Fixed length records
|
Fixed length read/write
Before terminals, computers commonly used punch card readers or paper tape input.
A common format before these devices were superseded by terminal technology was based on the Hollerith code, Hollerith code.
These input devices handled 80 columns per card and had a limited character set, encoded by punching holes in one or more rows of the card for each column.
These devices assumed/demanded a fixed line width of 80 characters, newlines were not required (and could not even be encoded in some systems).
Task
Write a program to read 80 column fixed length records (no newline terminators (but newline characters allowed in the data)) and then write out the reverse of each line as fixed length 80 column records.
Samples here use printable characters, but that is not a given with fixed length data. Filenames used are sample.txt, infile.dat, outfile.dat.
Note: There are no newlines, inputs and outputs are fixed at 80 columns, no more, no less, space padded. Fixed length data is 8 bit complete. NUL bytes of zero are allowed.
These fixed length formats are still in wide use on mainframes, with JCL and with COBOL (which commonly use EBCDIC encoding and not ASCII). Most of the large players in day to day financial transactions know all about fixed length records and the expression logical record length.
Sample data
To create the sample input file, use an editor that supports fixed length records or use a conversion utility. For instance, most GNU/Linux versions of dd support blocking and unblocking records with a conversion byte size.
Line 1...1.........2.........3.........4.........5.........6.........7.........8
Line 2
Line 3
Line 4
Line 6
Line 7
Indented line 8............................................................
Line 9 RT MARGIN
prompt$ dd if=sample.txt of=infile.dat cbs=80 conv=block
prompt$ dd if=infile.dat cbs=80 conv=unblock
Bonus round
Forth systems often include BLOCK words. A block is 1024 bytes. Source code is stored as 16 lines of 64 characters each (again, no newline character or sequence to mark the end of a line).
Write a program to convert a block file to text (using newlines). Trailing spaces should be excluded from the output.
Also demonstrate how to convert from a normal text file to block form. All lines either truncated or padded to 64 characters with no newline terminators. The last block filled to be exactly 1024 characters by adding blanks if needed. Assume a full range of 8 bit byte values for each character.
The COBOL example uses forth.txt and forth.blk filenames.
|
#zkl
|
zkl
|
Line 1...1.........2.........3.........4.........5.........6.........7.........8Line 2 Line 3 Line 4 Line 6 Line 7 Indented line 8............................................................Line 9 RT MARGIN
|
http://rosettacode.org/wiki/Floyd-Warshall_algorithm
|
Floyd-Warshall algorithm
|
The Floyd–Warshall algorithm is an algorithm for finding shortest paths in a weighted graph with positive or negative edge weights.
Task
Find the lengths of the shortest paths between all pairs of vertices of the given directed graph. Your code may assume that the input has already been checked for loops, parallel edges and negative cycles.
Print the pair, the distance and (optionally) the path.
Example
pair dist path
1 -> 2 -1 1 -> 3 -> 4 -> 2
1 -> 3 -2 1 -> 3
1 -> 4 0 1 -> 3 -> 4
2 -> 1 4 2 -> 1
2 -> 3 2 2 -> 1 -> 3
2 -> 4 4 2 -> 1 -> 3 -> 4
3 -> 1 5 3 -> 4 -> 2 -> 1
3 -> 2 1 3 -> 4 -> 2
3 -> 4 2 3 -> 4
4 -> 1 3 4 -> 2 -> 1
4 -> 2 -1 4 -> 2
4 -> 3 1 4 -> 2 -> 1 -> 3
See also
Floyd-Warshall Algorithm - step by step guide (youtube)
|
#Go
|
Go
|
package main
import (
"fmt"
"strconv"
)
// A Graph is the interface implemented by graphs that
// this algorithm can run on.
type Graph interface {
Vertices() []Vertex
Neighbors(v Vertex) []Vertex
Weight(u, v Vertex) int
}
// Nonnegative integer ID of vertex
type Vertex int
// ig is a graph of integers that satisfies the Graph interface.
type ig struct {
vert []Vertex
edges map[Vertex]map[Vertex]int
}
func (g ig) edge(u, v Vertex, w int) {
if _, ok := g.edges[u]; !ok {
g.edges[u] = make(map[Vertex]int)
}
g.edges[u][v] = w
}
func (g ig) Vertices() []Vertex { return g.vert }
func (g ig) Neighbors(v Vertex) (vs []Vertex) {
for k := range g.edges[v] {
vs = append(vs, k)
}
return vs
}
func (g ig) Weight(u, v Vertex) int { return g.edges[u][v] }
func (g ig) path(vv []Vertex) (s string) {
if len(vv) == 0 {
return ""
}
s = strconv.Itoa(int(vv[0]))
for _, v := range vv[1:] {
s += " -> " + strconv.Itoa(int(v))
}
return s
}
const Infinity = int(^uint(0) >> 1)
func FloydWarshall(g Graph) (dist map[Vertex]map[Vertex]int, next map[Vertex]map[Vertex]*Vertex) {
vert := g.Vertices()
dist = make(map[Vertex]map[Vertex]int)
next = make(map[Vertex]map[Vertex]*Vertex)
for _, u := range vert {
dist[u] = make(map[Vertex]int)
next[u] = make(map[Vertex]*Vertex)
for _, v := range vert {
dist[u][v] = Infinity
}
dist[u][u] = 0
for _, v := range g.Neighbors(u) {
v := v
dist[u][v] = g.Weight(u, v)
next[u][v] = &v
}
}
for _, k := range vert {
for _, i := range vert {
for _, j := range vert {
if dist[i][k] < Infinity && dist[k][j] < Infinity {
if dist[i][j] > dist[i][k]+dist[k][j] {
dist[i][j] = dist[i][k] + dist[k][j]
next[i][j] = next[i][k]
}
}
}
}
}
return dist, next
}
func Path(u, v Vertex, next map[Vertex]map[Vertex]*Vertex) (path []Vertex) {
if next[u][v] == nil {
return
}
path = []Vertex{u}
for u != v {
u = *next[u][v]
path = append(path, u)
}
return path
}
func main() {
g := ig{[]Vertex{1, 2, 3, 4}, make(map[Vertex]map[Vertex]int)}
g.edge(1, 3, -2)
g.edge(3, 4, 2)
g.edge(4, 2, -1)
g.edge(2, 1, 4)
g.edge(2, 3, 3)
dist, next := FloydWarshall(g)
fmt.Println("pair\tdist\tpath")
for u, m := range dist {
for v, d := range m {
if u != v {
fmt.Printf("%d -> %d\t%3d\t%s\n", u, v, d, g.path(Path(u, v, next)))
}
}
}
}
|
http://rosettacode.org/wiki/Function_definition
|
Function definition
|
A function is a body of code that returns a value.
The value returned may depend on arguments provided to the function.
Task
Write a definition of a function called "multiply" that takes two arguments and returns their product.
(Argument types should be chosen so as not to distract from showing how functions are created and values returned).
Related task
Function prototype
|
#Quack
|
Quack
|
fn multiply[ a; b ]
^ a * b
end
|
http://rosettacode.org/wiki/Function_definition
|
Function definition
|
A function is a body of code that returns a value.
The value returned may depend on arguments provided to the function.
Task
Write a definition of a function called "multiply" that takes two arguments and returns their product.
(Argument types should be chosen so as not to distract from showing how functions are created and values returned).
Related task
Function prototype
|
#Quackery
|
Quackery
|
[ * ] is multiply ( n n --> n )
|
http://rosettacode.org/wiki/Forward_difference
|
Forward difference
|
Task
Provide code that produces a list of numbers which is the nth order forward difference, given a non-negative integer (specifying the order) and a list of numbers.
The first-order forward difference of a list of numbers A is a new list B, where Bn = An+1 - An.
List B should have one fewer element as a result.
The second-order forward difference of A will be:
tdefmodule Diff do
def forward(arr,i\\1) do
forward(arr,[],i)
end
def forward([_|[]],diffs,i) do
if i == 1 do
IO.inspect diffs
else
forward(diffs,[],i-1)
end
end
def forward([val1|[val2|vals]],diffs,i) do
forward([val2|vals],diffs++[val2-val1],i)
end
end
The same as the first-order forward difference of B.
That new list will have two fewer elements than A and one less than B.
The goal of this task is to repeat this process up to the desired order.
For a more formal description, see the related Mathworld article.
Algorithmic options
Iterate through all previous forward differences and re-calculate a new array each time.
Use this formula (from Wikipedia):
Δ
n
[
f
]
(
x
)
=
∑
k
=
0
n
(
n
k
)
(
−
1
)
n
−
k
f
(
x
+
k
)
{\displaystyle \Delta ^{n}[f](x)=\sum _{k=0}^{n}{n \choose k}(-1)^{n-k}f(x+k)}
(Pascal's Triangle may be useful for this option.)
|
#K4
|
K4
|
fd:1_-':
|
http://rosettacode.org/wiki/Forward_difference
|
Forward difference
|
Task
Provide code that produces a list of numbers which is the nth order forward difference, given a non-negative integer (specifying the order) and a list of numbers.
The first-order forward difference of a list of numbers A is a new list B, where Bn = An+1 - An.
List B should have one fewer element as a result.
The second-order forward difference of A will be:
tdefmodule Diff do
def forward(arr,i\\1) do
forward(arr,[],i)
end
def forward([_|[]],diffs,i) do
if i == 1 do
IO.inspect diffs
else
forward(diffs,[],i-1)
end
end
def forward([val1|[val2|vals]],diffs,i) do
forward([val2|vals],diffs++[val2-val1],i)
end
end
The same as the first-order forward difference of B.
That new list will have two fewer elements than A and one less than B.
The goal of this task is to repeat this process up to the desired order.
For a more formal description, see the related Mathworld article.
Algorithmic options
Iterate through all previous forward differences and re-calculate a new array each time.
Use this formula (from Wikipedia):
Δ
n
[
f
]
(
x
)
=
∑
k
=
0
n
(
n
k
)
(
−
1
)
n
−
k
f
(
x
+
k
)
{\displaystyle \Delta ^{n}[f](x)=\sum _{k=0}^{n}{n \choose k}(-1)^{n-k}f(x+k)}
(Pascal's Triangle may be useful for this option.)
|
#Kotlin
|
Kotlin
|
// version 1.1.2
fun forwardDifference(ia: IntArray, order: Int): IntArray {
if (order < 0) throw IllegalArgumentException("Order must be non-negative")
if (order == 0) return ia
val size = ia.size
if (size == 0) return ia // same empty array
if (order >= size) return intArrayOf() // new empty array
var old = ia
var new = old
var count = order
while (count-- >= 1) {
new = IntArray(old.size - 1)
for (i in 0 until new.size) new[i] = old[i + 1] - old[i]
old = new
}
return new
}
fun printArray(ia: IntArray) {
print("[")
for (i in 0 until ia.size) {
print("%5d".format(ia[i]))
if (i < ia .size - 1) print(", ")
}
println("]")
}
fun main(args: Array<String>) {
val ia = intArrayOf(90, 47, 58, 29, 22, 32, 55, 5, 55, 73)
for (order in 0..ia.size) {
val fd = forwardDifference(ia, order)
print("%2d".format(order) + ": ")
printArray(fd)
}
}
|
http://rosettacode.org/wiki/Hello_world/Text
|
Hello world/Text
|
Hello world/Text is part of Short Circuit's Console Program Basics selection.
Task
Display the string Hello world! on a text console.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello world/Newbie
Hello world/Newline omission
Hello world/Standard error
Hello world/Web server
|
#xEec
|
xEec
|
h#10 h$! h$d h$l h$r h$o h$w h#32
h$o h$l h$l h$e h$H >o o$ p jno
|
http://rosettacode.org/wiki/Hello_world/Text
|
Hello world/Text
|
Hello world/Text is part of Short Circuit's Console Program Basics selection.
Task
Display the string Hello world! on a text console.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello world/Newbie
Hello world/Newline omission
Hello world/Standard error
Hello world/Web server
|
#XL
|
XL
|
use XL.UI.CONSOLE
WriteLn "Hello world!"
|
http://rosettacode.org/wiki/Formatted_numeric_output
|
Formatted numeric output
|
Task
Express a number in decimal as a fixed-length string with leading zeros.
For example, the number 7.125 could be expressed as 00007.125.
|
#Pascal
|
Pascal
|
procedure writeInFixedFormat(n: real);
const
wholeNumberPlaces = 5;
fractionalPlaces = 3;
zeroDigit = '0';
negative = '-';
var
signPresent: boolean;
i: integer;
begin
// NOTE: This does not catch “negative” zero.
signPresent := n < 0.0;
if signPresent then
begin
write(negative);
n := abs(n);
end;
// determine number of leading zeros
i := wholeNumberPlaces;
if n > 0 then
begin
i := i - trunc(ln(n) / ln(10));
end;
for i := i - 1 downto succ(ord(signPresent)) do
begin
write(zeroDigit);
end;
// writes n with
// - at least 0 characters in total
// - exactly fractionalPlaces post-radix digits
// rounded
write(n:0:fractionalPlaces);
end;
|
http://rosettacode.org/wiki/Four_bit_adder
|
Four bit adder
|
Task
"Simulate" a four-bit adder.
This design can be realized using four 1-bit full adders.
Each of these 1-bit full adders can be built with two half adders and an or gate. ;
Finally a half adder can be made using an xor gate and an and gate.
The xor gate can be made using two nots, two ands and one or.
Not, or and and, the only allowed "gates" for the task, can be "imitated" by using the bitwise operators of your language.
If there is not a bit type in your language, to be sure that the not does not "invert" all the other bits of the basic type (e.g. a byte) we are not interested in, you can use an extra nand (and then not) with the constant 1 on one input.
Instead of optimizing and reducing the number of gates used for the final 4-bit adder, build it in the most straightforward way, connecting the other "constructive blocks", in turn made of "simpler" and "smaller" ones.
Schematics of the "constructive blocks"
(Xor gate with ANDs, ORs and NOTs)
(A half adder)
(A full adder)
(A 4-bit adder)
Solutions should try to be as descriptive as possible, making it as easy as possible to identify "connections" between higher-order "blocks".
It is not mandatory to replicate the syntax of higher-order blocks in the atomic "gate" blocks, i.e. basic "gate" operations can be performed as usual bitwise operations, or they can be "wrapped" in a block in order to expose the same syntax of higher-order blocks, at implementers' choice.
To test the implementation, show the sum of two four-bit numbers (in binary).
|
#Lua
|
Lua
|
-- Build XOR from AND, OR and NOT
function xor (a, b) return (a and not b) or (b and not a) end
-- Can make half adder now XOR exists
function halfAdder (a, b) return xor(a, b), a and b end
-- Full adder is two half adders with carry outputs OR'd
function fullAdder (a, b, cIn)
local ha0s, ha0c = halfAdder(cIn, a)
local ha1s, ha1c = halfAdder(ha0s, b)
local cOut, s = ha0c or ha1c, ha1s
return cOut, s
end
-- Carry bits 'ripple' through adders, first returned value is overflow
function fourBitAdder (a3, a2, a1, a0, b3, b2, b1, b0) -- LSB-first
local fa0c, fa0s = fullAdder(a0, b0, false)
local fa1c, fa1s = fullAdder(a1, b1, fa0c)
local fa2c, fa2s = fullAdder(a2, b2, fa1c)
local fa3c, fa3s = fullAdder(a3, b3, fa2c)
return fa3c, fa3s, fa2s, fa1s, fa0s -- Return as MSB-first
end
-- Take string of noughts and ones, convert to native boolean type
function toBool (bitString)
local boolList, bit = {}
for digit = 1, 4 do
bit = string.sub(string.format("%04d", bitString), digit, digit)
if bit == "0" then table.insert(boolList, false) end
if bit == "1" then table.insert(boolList, true) end
end
return boolList
end
-- Take list of booleans, convert to string of binary digits (variadic)
function toBits (...)
local bStr = ""
for i, bool in pairs{...} do
if bool then bStr = bStr .. "1" else bStr = bStr .. "0" end
end
return bStr
end
-- Little driver function to neaten use of the adder
function add (n1, n2)
local A, B = toBool(n1), toBool(n2)
local v, s0, s1, s2, s3 = fourBitAdder( A[1], A[2], A[3], A[4],
B[1], B[2], B[3], B[4] )
return toBits(s0, s1, s2, s3), v
end
-- Main procedure (usage examples)
print("SUM", "OVERFLOW\n")
print(add(0001, 0001)) -- 1 + 1 = 2
print(add(0101, 1010)) -- 5 + 10 = 15
print(add(0000, 1111)) -- 0 + 15 = 15
print(add(0001, 1111)) -- 1 + 15 = 16 (causes overflow)
|
http://rosettacode.org/wiki/Fivenum
|
Fivenum
|
Many big data or scientific programs use boxplots to show distributions of data. In addition, sometimes saving large arrays for boxplots can be impractical and use extreme amounts of RAM. It can be useful to save large arrays as arrays with five numbers to save memory.
For example, the R programming language implements Tukey's five-number summary as the fivenum function.
Task
Given an array of numbers, compute the five-number summary.
Note
While these five numbers can be used to draw a boxplot, statistical packages will typically need extra data.
Moreover, while there is a consensus about the "box" of the boxplot, there are variations among statistical packages for the whiskers.
|
#Ada
|
Ada
|
with Ada.Text_IO; use Ada.Text_IO;
with Ada.Containers.Generic_Array_Sort;
procedure Main is
package Real_Io is new Float_IO (Long_Float);
use Real_Io;
type Data_Array is array (Natural range <>) of Long_Float;
subtype Five_Num_Type is Data_Array (0 .. 4);
procedure Sort is new Ada.Containers.Generic_Array_Sort
(Index_Type => Natural, Element_Type => Long_Float,
Array_Type => Data_Array);
function Median (X : Data_Array) return Long_Float with
Pre => X'Length > 0;
function Median (X : Data_Array) return Long_Float is
M : constant Natural := X'First + X'Last / 2;
begin
if X'Length rem 2 = 1 then
return X (M);
else
return (X (M - 1) + X (M)) / 2.0;
end if;
end Median;
procedure fivenum (X : Data_Array; Result : out Five_Num_Type) is
Temp : Data_Array := X;
m : Natural := X'Length / 2;
Lower_end : Natural := (if X'Length rem 2 = 0 then m - 1 else m);
begin
Sort (Temp);
Result (0) := Temp (Temp'First);
Result (2) := Median (Temp);
Result (4) := Temp (Temp'Last);
Result (1) := Median (Temp (1 .. Lower_end));
Result (3) := Median (Temp (m .. Temp'Last));
end fivenum;
procedure print (Result : Five_Num_Type; Aft : Natural) is
begin
Put ("[");
for I in Result'Range loop
Put (Item => Result (I), Fore => 1, Aft => Aft, Exp => 0);
if I < Result'Last then
Put (", ");
else
Put_Line ("]");
end if;
end loop;
New_Line;
end print;
X1 : Data_Array :=
(15.0, 6.0, 42.0, 41.0, 7.0, 36.0, 49.0, 40.0, 39.0, 47.0, 43.0);
X2 : Data_Array := (36.0, 40.0, 7.0, 39.0, 41.0, 15.0);
X3 : Data_Array :=
(0.140_828_34, 0.097_487_90, 1.731_315_07, 0.876_360_09, -1.950_595_94,
0.734_385_55, -0.030_357_26, 1.466_759_70, -0.746_213_49, -0.725_887_72,
0.639_051_60, 0.615_015_27, -0.989_837_80, -1.004_478_74, -0.627_594_69,
0.662_061_63, 1.043_120_09, -0.103_053_85, 0.757_756_34, 0.325_665_78);
Result : Five_Num_Type;
begin
fivenum (X1, Result);
print (Result, 1);
fivenum (X2, Result);
print (Result, 1);
fivenum (X3, Result);
print (Result, 9);
end Main;
|
http://rosettacode.org/wiki/Forest_fire
|
Forest fire
|
This page uses content from Wikipedia. The original article was at Forest-fire model. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Task
Implement the Drossel and Schwabl definition of the forest-fire model.
It is basically a 2D cellular automaton where each cell can be in three distinct states (empty, tree and burning) and evolves according to the following rules (as given by Wikipedia)
A burning cell turns into an empty cell
A tree will burn if at least one neighbor is burning
A tree ignites with probability f even if no neighbor is burning
An empty space fills with a tree with probability p
Neighborhood is the Moore neighborhood; boundary conditions are so that on the boundary the cells are always empty ("fixed" boundary condition).
At the beginning, populate the lattice with empty and tree cells according to a specific probability (e.g. a cell has the probability 0.5 to be a tree). Then, let the system evolve.
Task's requirements do not include graphical display or the ability to change parameters (probabilities p and f ) through a graphical or command line interface.
Related tasks
See Conway's Game of Life
See Wireworld.
|
#Ceylon
|
Ceylon
|
import ceylon.random { DefaultRandom }
abstract class Cell() of tree | dirt | burning {}
object tree extends Cell() { string => "A"; }
object dirt extends Cell() { string => " "; }
object burning extends Cell() { string => "#"; }
class Forest(Integer width, Integer height, Float f, Float p) {
value random = DefaultRandom();
function chance(Float probability) => random.nextFloat() < probability;
value sparked => chance(f);
value sprouted => chance(p);
alias Point => Integer[2];
interface Row => {Cell*};
object doubleBufferedGrid satisfies
Correspondence<Point, Cell> &
KeyedCorrespondenceMutator<Point, Cell> {
value grids = [
Array {
for (j in 0:height)
Array {
for (i in 0:width)
chance(0.5) then tree else dirt
}
},
Array {
for (j in 0:height)
Array.ofSize(width, dirt)
}
];
variable value showFirst = true;
value currentState => showFirst then grids.first else grids.last;
value nextState => showFirst then grids.last else grids.first;
shared void swapStates() => showFirst = !showFirst;
shared {Row*} rows => currentState;
shared actual Boolean defines(Point key) =>
let (x = key[0], y = key[1])
0 <= x < width && 0 <= y < height;
shared actual Cell? get(Point key) =>
let (x = key[0], y = key[1])
currentState.get(y)?.get(x);
shared actual void put(Point key, Cell cell) {
value [x, y] = key;
nextState.get(y)?.set(x, cell);
}
}
variable value evolutions = 0;
shared Integer generation => evolutions + 1;
shared void evolve() {
evolutions++;
function firesNearby(Integer x, Integer y) => {
for (j in y - 1 : 3)
for (i in x - 1 : 3)
doubleBufferedGrid[[i, j]]
}.coalesced.any(burning.equals);
for(j->row in doubleBufferedGrid.rows.indexed) {
for(i->cell in row.indexed) {
switch (cell)
case (burning) {
doubleBufferedGrid[[i, j]] = dirt;
}
case (dirt) {
doubleBufferedGrid[[i, j]] = sprouted then tree else dirt;
}
case (tree) {
doubleBufferedGrid[[i, j]] =
firesNearby(i, j) || sparked
then burning else tree;
}
}
}
doubleBufferedGrid.swapStates();
}
shared void display() {
void drawLine() => print("-".repeat(width + 2));
drawLine();
for (row in doubleBufferedGrid.rows) {
process.write("|");
for (cell in row) {
process.write(cell.string);
}
print("|");
}
drawLine();
}
}
shared void run() {
value forest = Forest(78, 38, 0.02, 0.03);
while (true) {
forest.display();
print("Generation ``forest.generation``");
print("Press enter for next generation or q and then enter to quit");
value input = process.readLine();
if (exists input, input.trimmed.lowercased == "q") {
return;
}
forest.evolve();
}
}
|
http://rosettacode.org/wiki/Flatten_a_list
|
Flatten a list
|
Task
Write a function to flatten the nesting in an arbitrary list of values.
Your program should work on the equivalent of this list:
[[1], 2, [[3, 4], 5], [[[]]], [[[6]]], 7, 8, []]
Where the correct result would be the list:
[1, 2, 3, 4, 5, 6, 7, 8]
Related task
Tree traversal
|
#BASIC256
|
BASIC256
|
sComma = "": sFlatter = ""
sString = "[[1], 2, [[3,4], 5], [[[]]], [[[6]]], 7, 8 []]"
For siCount = 1 To Length(sString)
If Instr("[] ,", Mid(sString, siCount, 1)) = 0 Then
sFlatter = sFlatter & sComma & Mid(sString, siCount, 1)
sComma = ", "
End If
Next siCount
Print "["; sFlatter; "]"
End
|
http://rosettacode.org/wiki/Flipping_bits_game
|
Flipping bits game
|
The game
Given an N×N square array of zeroes or ones in an initial configuration, and a target configuration of zeroes and ones.
The game is to transform one to the other in as few moves as possible by inverting whole numbered rows or whole lettered
columns at once (as one move).
In an inversion. any 1 becomes 0, and any 0 becomes 1 for that whole row or column.
Task
Create a program to score for the Flipping bits game.
The game should create an original random target configuration and a starting configuration.
Ensure that the starting position is never the target position.
The target position must be guaranteed as reachable from the starting position. (One possible way to do this is to generate the start position by legal flips from a random target position. The flips will always be reversible back to the target from the given start position).
The number of moves taken so far should be shown.
Show an example of a short game here, on this page, for a 3×3 array of bits.
|
#Fortran
|
Fortran
|
!Implemented by Anant Dixit (October 2014)
program flipping_bits
implicit none
character(len=*), parameter :: cfmt = "(A3)", ifmt = "(I3)"
integer :: N, i, j, io, seed(8), moves, input
logical, allocatable :: Brd(:,:), Trgt(:,:)
logical :: solved
double precision :: r
do
write(*,*) 'Enter the number of squares (between 1 and 10) you would like: '
read(*,*,iostat=io) N
if(N.gt.0 .and. N.le.10 .and. io.eq.0) exit
write(*,*) 'Please, an integer between 1 and 10'
end do
allocate(Brd(N,N),Trgt(N,N))
call date_and_time(values=seed)
call srand(1000*seed(7)+seed(8)+60000*seed(6))
do i = 1,N
do j = 1,N
r = rand()
if(r.gt.0.5D0) then
Brd(i,j) = .TRUE.
Trgt(i,j) = .TRUE.
else
Brd(i,j) = .FALSE.
Trgt(i,j) = .FALSE.
end if
end do
end do
! Random moves taken by the program to `create' a target
moves = N
do i = 1,moves
r = 1+2.0D0*dble(N)*rand() - 1.0D-17 !Only to make sure that the number is between 1 and 2N (less than 2N-1)
if(floor(r).le.N) then
do j = 1,N
Trgt(floor(r),j) = .NOT.Trgt(floor(r),j)
end do
else
r = r-N
do j = 1,N
Trgt(j,floor(r)) = .NOT.Trgt(j,floor(r))
end do
end if
end do
!This part checks if the target and the starting configurations are same or not.
do
input = N
call next_move(Brd,Trgt,N,input,solved)
call next_move(Brd,Trgt,N,input,solved)
if(solved) then
r = 1+2.0D0*dble(N)*rand() - 1.0D-17
if(floor(r).le.N) then
do j = 1,N
Trgt(floor(r),j) = .NOT.Trgt(floor(r),j)
end do
else
r = r-N
do j = 1,N
Trgt(j,floor(r)) = .NOT.Trgt(j,floor(r))
end do
end if
else
exit
end if
end do
write(*,*) 'Welcome to the Flipping Bits game!'
write(*,*) 'You have the current position'
moves = 0
call display(Brd,Trgt,N)
input = N
do
write(*,*) 'Number of moves so far:', moves
write(*,*) 'Select the column or row you wish to flip: '
read(*,*,iostat=io) input
if(io.eq.0 .and. input.gt.0 .and. input.le.(2*N)) then
moves = moves+1
write(*,*) 'Flipping ', input
call next_move(Brd,Trgt,N,input,solved)
call display(Brd,Trgt,N)
if(solved) exit
else
write(*,*) 'Please enter a valid column or row number. To quit, press Ctrl+C!'
end if
end do
write(*,*) 'Congratulations! You finished the game!'
write(*,ifmt,advance='no') moves
write(*,*) ' moves were taken by you!!'
deallocate(Brd,Trgt)
end program
subroutine display(Brd,Trgt,N)
implicit none
!arguments
integer :: N
logical :: Brd(N,N), Trgt(N,N)
!local
character(len=*), parameter :: cfmt = "(A3)", ifmt = "(I3)"
integer :: i, j
write(*,*) 'Current Configuration: '
do i = 0,N
if(i.eq.0) then
write(*,cfmt,advance='no') 'R/C'
write(*,cfmt,advance='no') ' | '
else
write(*,ifmt,advance='no') i
end if
end do
write(*,*)
do i = 0,N
if(i.eq.0) then
do j = 0,N+2
write(*,cfmt,advance='no') '---'
end do
else
write(*,ifmt,advance='no') i+N
write(*,cfmt,advance='no') ' | '
do j = 1,N
if(Brd(i,j)) then
write(*,ifmt,advance='no') 1
else
write(*,ifmt,advance='no') 0
end if
end do
end if
write(*,*)
end do
write(*,*)
write(*,*)
write(*,*) 'Target Configuration'
do i = 0,N
if(i.eq.0) then
write(*,cfmt,advance='no') 'R/C'
write(*,cfmt,advance='no') ' | '
else
write(*,ifmt,advance='no') i
end if
end do
write(*,*)
do i = 0,N
if(i.eq.0) then
do j = 0,N+2
write(*,cfmt,advance='no') '---'
end do
else
write(*,ifmt,advance='no') i+N
write(*,cfmt,advance='no') ' | '
do j = 1,N
if(Trgt(i,j)) then
write(*,ifmt,advance='no') 1
else
write(*,ifmt,advance='no') 0
end if
end do
end if
write(*,*)
end do
write(*,*)
write(*,*)
end subroutine
subroutine next_move(Brd,Trgt,N,input,solved)
implicit none
!arguments
integer :: N, input
logical :: Brd(N,N), Trgt(N,N), solved
!others
integer :: i,j
if(input.gt.N) then
input = input-N
do i = 1,N
Brd(input,i) = .not.Brd(input,i)
end do
else
do i = 1,N
Brd(i,input) = .not.Brd(i,input)
end do
end if
solved = .TRUE.
do i = 1,N
do j = 1,N
if( (.not.Brd(i,j).and.Trgt(i,j)) .or. (Brd(i,j).and..not.Trgt(i,j)) ) then
solved = .FALSE.
exit
end if
end do
if(.not.solved) exit
end do
end subroutine
|
http://rosettacode.org/wiki/First_power_of_2_that_has_leading_decimal_digits_of_12
|
First power of 2 that has leading decimal digits of 12
|
(This task is taken from a Project Euler problem.)
(All numbers herein are expressed in base ten.)
27 = 128 and 7 is
the first power of 2 whose leading decimal digits are 12.
The next power of 2 whose leading decimal digits
are 12 is 80,
280 = 1208925819614629174706176.
Define p(L,n) to be the nth-smallest
value of j such that the base ten representation
of 2j begins with the digits of L .
So p(12, 1) = 7 and
p(12, 2) = 80
You are also given that:
p(123, 45) = 12710
Task
find:
p(12, 1)
p(12, 2)
p(123, 45)
p(123, 12345)
p(123, 678910)
display the results here, on this page.
|
#C.2B.2B
|
C++
|
// a mini chrestomathy solution
#include <string>
#include <chrono>
#include <cmath>
#include <locale>
using namespace std;
using namespace chrono;
// translated from java example
unsigned int js(int l, int n) {
unsigned int res = 0, f = 1;
double lf = log(2) / log(10), ip;
for (int i = l; i > 10; i /= 10) f *= 10;
while (n > 0)
if ((int)(f * pow(10, modf(++res * lf, &ip))) == l) n--;
return res;
}
// translated from go integer example (a.k.a. go translation of pascal alternative example)
unsigned int gi(int ld, int n) {
string Ls = to_string(ld);
unsigned int res = 0, count = 0; unsigned long long f = 1;
for (int i = 1; i <= 18 - Ls.length(); i++) f *= 10;
const unsigned long long ten18 = 1e18; unsigned long long probe = 1;
do {
probe <<= 1; res++; if (probe >= ten18) {
do {
if (probe >= ten18) probe /= 10;
if (probe / f == ld) if (++count >= n) { count--; break; }
probe <<= 1; res++;
} while (1);
}
string ps = to_string(probe);
if (ps.substr(0, min(Ls.length(), ps.length())) == Ls) if (++count >= n) break;
} while (1);
return res;
}
// translated from pascal alternative example
unsigned int pa(int ld, int n) {
const double L_float64 = pow(2, 64);
const unsigned long long Log10_2_64 = (unsigned long long)(L_float64 * log(2) / log(10));
double Log10Num; unsigned long long LmtUpper, LmtLower, Frac64;
int res = 0, dgts = 1, cnt;
for (int i = ld; i >= 10; i /= 10) dgts *= 10;
Log10Num = log((ld + 1.0) / dgts) / log(10);
// '316' was a limit
if (Log10Num >= 0.5) {
LmtUpper = (ld + 1.0) / dgts < 10.0 ? (unsigned long long)(Log10Num * (L_float64 * 0.5)) * 2 + (unsigned long long)(Log10Num * 2) : 0;
Log10Num = log((double)ld / dgts) / log(10);
LmtLower = (unsigned long long)(Log10Num * (L_float64 * 0.5)) * 2 + (unsigned long long)(Log10Num * 2);
} else {
LmtUpper = (unsigned long long)(Log10Num * L_float64);
LmtLower = (unsigned long long)(log((double)ld / dgts) / log(10) * L_float64);
}
cnt = 0; Frac64 = 0; if (LmtUpper != 0) {
do {
res++; Frac64 += Log10_2_64;
if ((Frac64 >= LmtLower) & (Frac64 < LmtUpper))
if (++cnt >= n) break;
} while (1);
} else { // '999..'
do {
res++; Frac64 += Log10_2_64;
if (Frac64 >= LmtLower) if (++cnt >= n) break;
} while (1);
};
return res;
}
int params[] = { 12, 1, 12, 2, 123, 45, 123, 12345, 123, 678910, 99, 1 };
void doOne(string name, unsigned int (*func)(int a, int b)) {
printf("%s version:\n", name.c_str());
auto start = steady_clock::now();
for (int i = 0; i < size(params); i += 2)
printf("p(%3d, %6d) = %'11u\n", params[i], params[i + 1], func(params[i], params[i + 1]));
printf("Took %f seconds\n\n", duration<double>(steady_clock::now() - start).count());
}
int main() {
setlocale(LC_ALL, "");
doOne("java simple", js);
doOne("go integer", gi);
doOne("pascal alternative", pa);
}
|
http://rosettacode.org/wiki/First-class_functions/Use_numbers_analogously
|
First-class functions/Use numbers analogously
|
In First-class functions, a language is showing how its manipulation of functions is similar to its manipulation of other types.
This tasks aim is to compare and contrast a language's implementation of first class functions, with its normal handling of numbers.
Write a program to create an ordered collection of a mixture of literally typed and expressions producing a real number, together with another ordered collection of their multiplicative inverses. Try and use the following pseudo-code to generate the numbers for the ordered collections:
x = 2.0
xi = 0.5
y = 4.0
yi = 0.25
z = x + y
zi = 1.0 / ( x + y )
Create a function multiplier, that given two numbers as arguments returns a function that when called with one argument, returns the result of multiplying the two arguments to the call to multiplier that created it and the argument in the call:
new_function = multiplier(n1,n2)
# where new_function(m) returns the result of n1 * n2 * m
Applying the multiplier of a number and its inverse from the two ordered collections of numbers in pairs, show that the result in each case is one.
Compare and contrast the resultant program with the corresponding entry in First-class functions. They should be close.
To paraphrase the task description: Do what was done before, but with numbers rather than functions
|
#C.2B.2B
|
C++
|
#include <array>
#include <iostream>
int main()
{
double x = 2.0;
double xi = 0.5;
double y = 4.0;
double yi = 0.25;
double z = x + y;
double zi = 1.0 / ( x + y );
const std::array values{x, y, z};
const std::array inverses{xi, yi, zi};
auto multiplier = [](double a, double b)
{
return [=](double m){return a * b * m;};
};
for(size_t i = 0; i < values.size(); ++i)
{
auto new_function = multiplier(values[i], inverses[i]);
double value = new_function(i + 1.0);
std::cout << value << "\n";
}
}
|
http://rosettacode.org/wiki/Flow-control_structures
|
Flow-control structures
|
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
Document common flow-control structures.
One common example of a flow-control structure is the goto construct.
Note that Conditional Structures and Loop Structures have their own articles/categories.
Related tasks
Conditional Structures
Loop Structures
|
#GW-BASIC
|
GW-BASIC
|
10 LET a=1
20 IF a=2 THEN PRINT "This is a conditional statement"
30 IF a=1 THEN GOTO 50: REM a conditional jump
40 PRINT "This statement will be skipped"
50 PRINT ("Hello" AND (1=2)): REM This does NOT PRINT
100 PRINT "Endless loop"
110 GOTO 100:REM an unconditional jump
|
http://rosettacode.org/wiki/Flow-control_structures
|
Flow-control structures
|
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
Document common flow-control structures.
One common example of a flow-control structure is the goto construct.
Note that Conditional Structures and Loop Structures have their own articles/categories.
Related tasks
Conditional Structures
Loop Structures
|
#Haskell
|
Haskell
|
import Control.Monad
import Control.Monad.Trans
import Control.Monad.Exit
main = do
runExitTMaybe $ do
forM_ [1..5] $ \x -> do
forM_ [1..5] $ \y -> do
lift $ print (x, y)
when (x == 3 && y == 2) $
exitWith ()
putStrLn "Done."
|
http://rosettacode.org/wiki/Four_is_magic
|
Four is magic
|
Task
Write a subroutine, function, whatever it may be called in your language, that takes an integer number and returns an English text sequence starting with the English cardinal representation of that integer, the word 'is' and then the English cardinal representation of the count of characters that made up the first word, followed by a comma.
Continue the sequence by using the previous count word as the first word of the next phrase, append 'is' and the cardinal count of the letters in that word.
Continue until you reach four. Since four has four characters, finish by adding the words 'four is magic' and a period. All integers will eventually wind up at four.
For instance, suppose your are given the integer 3. Convert 3 to Three, add is , then the cardinal character count of three, or five, with a comma to separate if from the next phrase. Continue the sequence five is four, (five has four letters), and finally, four is magic.
Three is five, five is four, four is magic.
For reference, here are outputs for 0 through 9.
Zero is four, four is magic.
One is three, three is five, five is four, four is magic.
Two is three, three is five, five is four, four is magic.
Three is five, five is four, four is magic.
Four is magic.
Five is four, four is magic.
Six is three, three is five, five is four, four is magic.
Seven is five, five is four, four is magic.
Eight is five, five is four, four is magic.
Nine is four, four is magic.
Some task guidelines
You may assume the input will only contain integer numbers.
Cardinal numbers between 20 and 100 may use either hyphens or spaces as word separators but they must use a word separator. (23 is twenty three or twenty-three not twentythree.)
Cardinal number conversions should follow the English short scale. (billion is 1e9, trillion is 1e12, etc.)
Cardinal numbers should not include commas. (20140 is twenty thousand one hundred forty not twenty thousand, one hundred forty.)
When converted to a string, 100 should be one hundred, not a hundred or hundred, 1000 should be one thousand, not a thousand or thousand.
When converted to a string, there should be no and in the cardinal string. 130 should be one hundred thirty not one hundred and thirty.
When counting characters, count all of the characters in the cardinal number including spaces and hyphens. One hundred fifty-one should be 21 not 18.
The output should follow the format "N is K, K is M, M is ... four is magic." (unless the input is 4, in which case the output should simply be "four is magic.")
The output can either be the return value from the function, or be displayed from within the function.
You are encouraged, though not mandated to use proper sentence capitalization.
You may optionally support negative numbers. -7 is negative seven.
Show the output here for a small representative sample of values, at least 5 but no more than 25. You are free to choose which which numbers to use for output demonstration.
You can choose to use a library, (module, external routine, whatever) to do the cardinal conversions as long as the code is easily and freely available to the public.
If you roll your own, make the routine accept at minimum any integer from 0 up to 999999. If you use a pre-made library, support at least up to unsigned 64 bit integers. (or the largest integer supported in your language if it is less.)
Four is magic is a popular code-golf task. This is not code golf. Write legible, idiomatic and well formatted code.
Related tasks
Four is the number of_letters in the ...
Look-and-say sequence
Number names
Self-describing numbers
Summarize and say sequence
Spelling of ordinal numbers
De Bruijn sequences
|
#Ring
|
Ring
|
/* Checking numbers from 0 to 10 */
for c = 0 to 10
See checkmagic(c) + NL
next
/* The functions */
Func CheckMagic numb
CardinalN = ""
Result = ""
if isnumber(numb) = false or numb < 0 or numb > 999_999_999_999_999
Return "ERROR: Number entered is incorrect"
ok
if numb = 4
Result = "Four is magic."
else
While True
if CardinalN = "four"
Result += "four is magic"
exit
ok
strnumb = StringNumber(numb)
CardinalN = StringNumber(len(strnumb))
Result += strnumb + " is " + CardinalN + ", "
numb = len(strnumb)
End
Result += "."
Result = upper(Result[1]) + Right(Result, len(Result) -1)
ok
Return Result
Func StringNumber cnumb
NumStr = [:n0 = "zero", :n1 = "one", :n2 = "two", :n3 = "three", :n4 = "four", :n5 = "five",
:n6 = "six", :n7 = "seven", :n8 = "eight", :n9 = "nine", :n10 = "ten",
:n11 = "eleven", :n12 = "twelve", :n13 = "thirteen", :n14 = "fourteen", :n15 = "fifteen",
:n16 = "sixteen", :n17 = "seventeen", :n18 = "eighteen", :n19 = "nineteen",
:n20 = "twenty", :n30 = "thirty", :n40 = "fourty", :n50 = "fifty", :n60 = "sixty", :n70 = "seventy", :n80 = "eighty", :n90 = "ninety"]
numLev = [:l1 = "", :l2 = "thousand", :l3 = "million", :l4 = "billion", :l5 = "trillion"]
Result = ""
if cnumb > 0
decimals(0)
snumb = string((cnumb))
lnumb = [""]
fl = floor(len(snumb) / 3)
if fl > 0
for i = 1 to fl
lnumb[i] = right(snumb, 3)
snumb = left(snumb, len(snumb) -3)
lnumb + ""
next
if (len(snumb) % 3) > 0
lnumb[len(lnumb)] = snumb
else
del(lnumb, len(lnumb))
ok
else
lnumb[1] = snumb
ok
for l = len(lnumb) to 1 step -1
bnumb = lnumb[l]
bResult = ""
if number(bnumb) != 0
for n = len(bnumb) to 1 step -1
if (len(bnumb) = 3 and n = 2) or (len(bnumb) = 2 and n = 1)
if number(bnumb[n]) > 1
eval("bResult = NumStr[:n" + bnumb[n] + "0] + ' ' + bResult")
elseif number(bnumb[n]) = 1
eval("bResult = NumStr[:n" + bnumb[n] + bnumb[n+1] + "] + ' ' + bResult")
ok
else
if len(bnumb) = 3 and n = 1 and number(bnumb[1]) > 0
if trim(bResult) != ""
bResult = " " + bResult
ok
if number(bnumb[1]) > 1
bResult = "hundreds" + bResult
else
bResult = "hundred" + bResult
ok
if left(trim(bResult), 7) = "hundred"
bResult = bResult + " "
ok
ok
if (len(bnumb) = 3 and n = 1 and number(bnumb[1]) = 0) OR (len(bnumb) = n and number(bnumb[n]) = 0) OR (len(bnumb) = 3 and number(bnumb[2]) = 1) OR (len(bnumb) = 2 and number(bnumb[1]) = 1)
loop
ok
eval("bResult = NumStr[:n" + bnumb[n] + "] + ' ' + bResult")
ok
next
Result = Result + bResult
if l > 1
if number(bnumb) > 1
eval("Result = Result + numLev[:l" + l + "] + 's ' ")
else
eval("Result = Result + numLev[:l" + l + "] + ' ' ")
ok
ok
ok
next
else
Result = Result + NumStr[:n0]
ok
Return trim(Result)
|
http://rosettacode.org/wiki/Four_is_magic
|
Four is magic
|
Task
Write a subroutine, function, whatever it may be called in your language, that takes an integer number and returns an English text sequence starting with the English cardinal representation of that integer, the word 'is' and then the English cardinal representation of the count of characters that made up the first word, followed by a comma.
Continue the sequence by using the previous count word as the first word of the next phrase, append 'is' and the cardinal count of the letters in that word.
Continue until you reach four. Since four has four characters, finish by adding the words 'four is magic' and a period. All integers will eventually wind up at four.
For instance, suppose your are given the integer 3. Convert 3 to Three, add is , then the cardinal character count of three, or five, with a comma to separate if from the next phrase. Continue the sequence five is four, (five has four letters), and finally, four is magic.
Three is five, five is four, four is magic.
For reference, here are outputs for 0 through 9.
Zero is four, four is magic.
One is three, three is five, five is four, four is magic.
Two is three, three is five, five is four, four is magic.
Three is five, five is four, four is magic.
Four is magic.
Five is four, four is magic.
Six is three, three is five, five is four, four is magic.
Seven is five, five is four, four is magic.
Eight is five, five is four, four is magic.
Nine is four, four is magic.
Some task guidelines
You may assume the input will only contain integer numbers.
Cardinal numbers between 20 and 100 may use either hyphens or spaces as word separators but they must use a word separator. (23 is twenty three or twenty-three not twentythree.)
Cardinal number conversions should follow the English short scale. (billion is 1e9, trillion is 1e12, etc.)
Cardinal numbers should not include commas. (20140 is twenty thousand one hundred forty not twenty thousand, one hundred forty.)
When converted to a string, 100 should be one hundred, not a hundred or hundred, 1000 should be one thousand, not a thousand or thousand.
When converted to a string, there should be no and in the cardinal string. 130 should be one hundred thirty not one hundred and thirty.
When counting characters, count all of the characters in the cardinal number including spaces and hyphens. One hundred fifty-one should be 21 not 18.
The output should follow the format "N is K, K is M, M is ... four is magic." (unless the input is 4, in which case the output should simply be "four is magic.")
The output can either be the return value from the function, or be displayed from within the function.
You are encouraged, though not mandated to use proper sentence capitalization.
You may optionally support negative numbers. -7 is negative seven.
Show the output here for a small representative sample of values, at least 5 but no more than 25. You are free to choose which which numbers to use for output demonstration.
You can choose to use a library, (module, external routine, whatever) to do the cardinal conversions as long as the code is easily and freely available to the public.
If you roll your own, make the routine accept at minimum any integer from 0 up to 999999. If you use a pre-made library, support at least up to unsigned 64 bit integers. (or the largest integer supported in your language if it is less.)
Four is magic is a popular code-golf task. This is not code golf. Write legible, idiomatic and well formatted code.
Related tasks
Four is the number of_letters in the ...
Look-and-say sequence
Number names
Self-describing numbers
Summarize and say sequence
Spelling of ordinal numbers
De Bruijn sequences
|
#Ruby
|
Ruby
|
module NumberToWord
NUMBERS = { # taken from https://en.wikipedia.org/wiki/Names_of_large_numbers#cite_ref-a_14-3
1 => 'one',
2 => 'two',
3 => 'three',
4 => 'four',
5 => 'five',
6 => 'six',
7 => 'seven',
8 => 'eight',
9 => 'nine',
10 => 'ten',
11 => 'eleven',
12 => 'twelve',
13 => 'thirteen',
14 => 'fourteen',
15 => 'fifteen',
16 => 'sixteen',
17 => 'seventeen',
18 => 'eighteen',
19 => 'nineteen',
20 => 'twenty',
30 => 'thirty',
40 => 'forty',
50 => 'fifty',
60 => 'sixty',
70 => 'seventy',
80 => 'eighty',
90 => 'ninety',
100 => 'hundred',
1000 => 'thousand',
10 ** 6 => 'million',
10 ** 9 => 'billion',
10 ** 12 => 'trillion',
10 ** 15 => 'quadrillion',
10 ** 18 => 'quintillion',
10 ** 21 => 'sextillion',
10 ** 24 => 'septillion',
10 ** 27 => 'octillion',
10 ** 30 => 'nonillion',
10 ** 33 => 'decillion'}.reverse_each.to_h
refine Integer do
def to_english
return 'zero' if i.zero?
words = self < 0 ? ['negative'] : []
i = self.abs
NUMBERS.each do |k, v|
if k <= i then
times = i/k
words << times.to_english if k >= 100
words << v
i -= times * k
end
return words.join(" ") if i.zero?
end
end
end
end
using NumberToWord
def magic4(n)
words = []
until n == 4
s = n.to_english
n = s.size
words << "#{s} is #{n.to_english}"
end
words << "four is magic."
words.join(", ").capitalize
end
[0, 4, 6, 11, 13, 75, 337, -164, 9_876_543_209].each{|n| puts magic4(n) }
|
http://rosettacode.org/wiki/Floyd%27s_triangle
|
Floyd's triangle
|
Floyd's triangle lists the natural numbers in a right triangle aligned to the left where
the first row is 1 (unity)
successive rows start towards the left with the next number followed by successive naturals listing one more number than the line above.
The first few lines of a Floyd triangle looks like this:
1
2 3
4 5 6
7 8 9 10
11 12 13 14 15
Task
Write a program to generate and display here the first n lines of a Floyd triangle.
(Use n=5 and n=14 rows).
Ensure that when displayed in a mono-space font, the numbers line up in vertical columns as shown and that only one space separates numbers of the last row.
|
#BASIC
|
BASIC
|
100 :
110 REM FLOYD'S TRIANGLE
120 :
130 DEF FN Q(A) = INT ( LOG (A) / LOG (10)) + 1
140 N = 14
150 DIM P(N): P(0) = - 1: FOR J = 1 TO N: I = (N * N - N) / 2 + J
160 P(J) = P(J - 1) + FN Q(I) + 1: NEXT J
200 FOR R = 1 TO N: FOR C = 1 TO R
210 NR = NR + 1:COL = P(C) - ( FN Q(NR) - 1)
220 HTAB COL: PRINT NR;: NEXT C
230 PRINT : NEXT R
|
http://rosettacode.org/wiki/Floyd-Warshall_algorithm
|
Floyd-Warshall algorithm
|
The Floyd–Warshall algorithm is an algorithm for finding shortest paths in a weighted graph with positive or negative edge weights.
Task
Find the lengths of the shortest paths between all pairs of vertices of the given directed graph. Your code may assume that the input has already been checked for loops, parallel edges and negative cycles.
Print the pair, the distance and (optionally) the path.
Example
pair dist path
1 -> 2 -1 1 -> 3 -> 4 -> 2
1 -> 3 -2 1 -> 3
1 -> 4 0 1 -> 3 -> 4
2 -> 1 4 2 -> 1
2 -> 3 2 2 -> 1 -> 3
2 -> 4 4 2 -> 1 -> 3 -> 4
3 -> 1 5 3 -> 4 -> 2 -> 1
3 -> 2 1 3 -> 4 -> 2
3 -> 4 2 3 -> 4
4 -> 1 3 4 -> 2 -> 1
4 -> 2 -1 4 -> 2
4 -> 3 1 4 -> 2 -> 1 -> 3
See also
Floyd-Warshall Algorithm - step by step guide (youtube)
|
#Groovy
|
Groovy
|
class FloydWarshall {
static void main(String[] args) {
int[][] weights = [[1, 3, -2], [2, 1, 4], [2, 3, 3], [3, 4, 2], [4, 2, -1]]
int numVertices = 4
floydWarshall(weights, numVertices)
}
static void floydWarshall(int[][] weights, int numVertices) {
double[][] dist = new double[numVertices][numVertices]
for (double[] row : dist) {
Arrays.fill(row, Double.POSITIVE_INFINITY)
}
for (int[] w : weights) {
dist[w[0] - 1][w[1] - 1] = w[2]
}
int[][] next = new int[numVertices][numVertices]
for (int i = 0; i < next.length; i++) {
for (int j = 0; j < next.length; j++) {
if (i != j) {
next[i][j] = j + 1
}
}
}
for (int k = 0; k < numVertices; k++) {
for (int i = 0; i < numVertices; i++) {
for (int j = 0; j < numVertices; j++) {
if (dist[i][k] + dist[k][j] < dist[i][j]) {
dist[i][j] = dist[i][k] + dist[k][j]
next[i][j] = next[i][k]
}
}
}
}
printResult(dist, next)
}
static void printResult(double[][] dist, int[][] next) {
println("pair dist path")
for (int i = 0; i < next.length; i++) {
for (int j = 0; j < next.length; j++) {
if (i != j) {
int u = i + 1
int v = j + 1
String path = String.format("%d -> %d %2d %s", u, v, (int) dist[i][j], u)
boolean loop = true
while (loop) {
u = next[u - 1][v - 1]
path += " -> " + u
loop = u != v
}
println(path)
}
}
}
}
}
|
http://rosettacode.org/wiki/Function_definition
|
Function definition
|
A function is a body of code that returns a value.
The value returned may depend on arguments provided to the function.
Task
Write a definition of a function called "multiply" that takes two arguments and returns their product.
(Argument types should be chosen so as not to distract from showing how functions are created and values returned).
Related task
Function prototype
|
#R
|
R
|
mult <- function(a,b) a*b
|
http://rosettacode.org/wiki/Forward_difference
|
Forward difference
|
Task
Provide code that produces a list of numbers which is the nth order forward difference, given a non-negative integer (specifying the order) and a list of numbers.
The first-order forward difference of a list of numbers A is a new list B, where Bn = An+1 - An.
List B should have one fewer element as a result.
The second-order forward difference of A will be:
tdefmodule Diff do
def forward(arr,i\\1) do
forward(arr,[],i)
end
def forward([_|[]],diffs,i) do
if i == 1 do
IO.inspect diffs
else
forward(diffs,[],i-1)
end
end
def forward([val1|[val2|vals]],diffs,i) do
forward([val2|vals],diffs++[val2-val1],i)
end
end
The same as the first-order forward difference of B.
That new list will have two fewer elements than A and one less than B.
The goal of this task is to repeat this process up to the desired order.
For a more formal description, see the related Mathworld article.
Algorithmic options
Iterate through all previous forward differences and re-calculate a new array each time.
Use this formula (from Wikipedia):
Δ
n
[
f
]
(
x
)
=
∑
k
=
0
n
(
n
k
)
(
−
1
)
n
−
k
f
(
x
+
k
)
{\displaystyle \Delta ^{n}[f](x)=\sum _{k=0}^{n}{n \choose k}(-1)^{n-k}f(x+k)}
(Pascal's Triangle may be useful for this option.)
|
#Lambdatalk
|
Lambdatalk
|
{def fdiff
{lambda {:l}
{A.new
{S.map {{lambda {:l :i} {- {A.get {+ :i 1} :l} {A.get :i :l}} } :l}
{S.serie 0 {- {A.length :l} 2}}}}}}
-> fdiff
{def disp
{lambda {:l}
{if {A.empty? {A.rest :l}}
then else {let { {:l {fdiff :l}} } {br}:l {disp :l}}}}}
-> disp
{def L {A.new 90 47 58 29 22 32 55 5 55 73}}
-> L
{disp {L}}
->
[-43,11,-29,-7,10,23,-50,50,18]
[54,-40,22,17,13,-73,100,-32]
[-94,62,-5,-4,-86,173,-132]
[156,-67,1,-82,259,-305]
[-223,68,-83,341,-564]
[291,-151,424,-905]
[-442,575,-1329]
[1017,-1904]
[-2921]
|
http://rosettacode.org/wiki/Hello_world/Text
|
Hello world/Text
|
Hello world/Text is part of Short Circuit's Console Program Basics selection.
Task
Display the string Hello world! on a text console.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello world/Newbie
Hello world/Newline omission
Hello world/Standard error
Hello world/Web server
|
#XLISP
|
XLISP
|
(DISPLAY "Hello world!")
(NEWLINE)
|
http://rosettacode.org/wiki/Formatted_numeric_output
|
Formatted numeric output
|
Task
Express a number in decimal as a fixed-length string with leading zeros.
For example, the number 7.125 could be expressed as 00007.125.
|
#Perl
|
Perl
|
printf "%09.3f\n", 7.125;
|
http://rosettacode.org/wiki/Formatted_numeric_output
|
Formatted numeric output
|
Task
Express a number in decimal as a fixed-length string with leading zeros.
For example, the number 7.125 could be expressed as 00007.125.
|
#Phix
|
Phix
|
printf(1,"%09.3f\n",7.125)
|
http://rosettacode.org/wiki/Four_bit_adder
|
Four bit adder
|
Task
"Simulate" a four-bit adder.
This design can be realized using four 1-bit full adders.
Each of these 1-bit full adders can be built with two half adders and an or gate. ;
Finally a half adder can be made using an xor gate and an and gate.
The xor gate can be made using two nots, two ands and one or.
Not, or and and, the only allowed "gates" for the task, can be "imitated" by using the bitwise operators of your language.
If there is not a bit type in your language, to be sure that the not does not "invert" all the other bits of the basic type (e.g. a byte) we are not interested in, you can use an extra nand (and then not) with the constant 1 on one input.
Instead of optimizing and reducing the number of gates used for the final 4-bit adder, build it in the most straightforward way, connecting the other "constructive blocks", in turn made of "simpler" and "smaller" ones.
Schematics of the "constructive blocks"
(Xor gate with ANDs, ORs and NOTs)
(A half adder)
(A full adder)
(A 4-bit adder)
Solutions should try to be as descriptive as possible, making it as easy as possible to identify "connections" between higher-order "blocks".
It is not mandatory to replicate the syntax of higher-order blocks in the atomic "gate" blocks, i.e. basic "gate" operations can be performed as usual bitwise operations, or they can be "wrapped" in a block in order to expose the same syntax of higher-order blocks, at implementers' choice.
To test the implementation, show the sum of two four-bit numbers (in binary).
|
#M2000_Interpreter
|
M2000 Interpreter
|
Module FourBitAdder {
Flush
dim not(0 to 1),and(0 to 1, 0 to 1),or(0 to 1, 0 to 1)
not(0)=1,0
and(0,0)=0,0,0,1
or(0,0)=0,1,1,1
xor=lambda not(),and(),or() (a,b)-> or(and(a, not(b)), and(b, not(a)))
ha=lambda xor, and() (a,b, &s, &c)->{
s=xor(a,b)
c=and(a,b)
}
fa=lambda ha, or() (a, b, c0, &s, &c1)->{
def sa,ca,cb
call ha(a, c0, &sa, &ca)
call ha(sa, b, &s,&cb)
c1=or(ca,cb)
}
add4=lambda fa (inpA(), inpB(), &v, &out()) ->{
dim carry(0 to 4)=0
carry(0)=v \\ 0 or 1 borrow
for i=0 to 3
\\ mm=fa(InpA(i), inpB(i), carry(i), &out(i), &carry(i+1)) ' same as this
Call fa(InpA(i), inpB(i), carry(i), &out(i), &carry(i+1))
next
v=carry(4)
}
dim res(0 to 3)=-1, low()
source=lambda->{
shift 1, -stack.size ' reverse stack items
=array([]) ' convert current stack to array, empty current stack
}
def v, k, k_low
Print "First Example 4-bit"
Print "A", "", 1, 0, 1, 0
Print "B", "", 1, 0, 0, 1
call add4(source(1,0,1,0), source(1,0,0,1), &v, &res())
k=each(res() end to start) ' k is an iterator, now configure to read items in reverse
Print "A+B",v, k ' print 1 0 0 1 1
Print "Second Example 4-bit"
v-=v
Print "A", "", 0, 1, 1, 0
Print "B", "", 0, 1, 1, 1
call add4(source(0,1,1,0), source(0,1,1,1), &v, &res())
k=each(res() end to start) ' k is an iterator, now configure to read items in reverse
Print "A+B",v, k ' print 0 1 1 0 1
Print "Third Example 8-bit"
v-=v
Print "A ", "", 1, 0, 0, 0, 0, 1, 1, 0
Print "B ", "", 1, 1, 1, 1, 1, 1, 1, 1
call add4(source(0,1,1,0), source(1,1,1,1), &v, &res())
low()=res() ' a copy of res()
' v passed to second adder
dim res(0 to 3)=-1
call add4(source(1,0,0,0), source(1,1,1,1), &v, &res())
k_low=each(low() end to start) ' k_low is an iterator, now configure to read items in reverse
k=each(res() end to start) ' k is an iterator, now configure to read items in reverse
Print "A+B",v, k, k_low ' print 1 1 0 0 0 0 1 0 1
}
FourBitAdder
|
http://rosettacode.org/wiki/Fivenum
|
Fivenum
|
Many big data or scientific programs use boxplots to show distributions of data. In addition, sometimes saving large arrays for boxplots can be impractical and use extreme amounts of RAM. It can be useful to save large arrays as arrays with five numbers to save memory.
For example, the R programming language implements Tukey's five-number summary as the fivenum function.
Task
Given an array of numbers, compute the five-number summary.
Note
While these five numbers can be used to draw a boxplot, statistical packages will typically need extra data.
Moreover, while there is a consensus about the "box" of the boxplot, there are variations among statistical packages for the whiskers.
|
#ALGOL_68
|
ALGOL 68
|
BEGIN # construct an R-style fivenum function #
PR read "rows.incl.a68" PR
PROC fivenum = ( []REAL array )[]REAL:
BEGIN
INT n = ( UPB array + 1 ) - LWB array;
[ 1 : n ]REAL x := array[ AT 1 ];
QUICKSORT x FROMELEMENT LWB x TOELEMENT UPB x;
REAL n4 = ( ( ( n + IF ODD n THEN 3 ELSE 2 FI ) / 2 ) / 2 ) ;
[]REAL d = ( 1, n4, ( n + 1 ) / 2, n + 1 - n4, n );
[ 1 : 5 ]REAL sum_array;
FOR e TO 5 DO
INT fl = ENTIER d[ e ];
INT ce = IF fl < d[ e ] THEN 1 + fl ELSE fl FI;
sum_array[ e ] := 0.5 * ( x[ fl ] + x[ ce ] )
OD;
sum_array
END # five num # ;
SHOW fivenum( ( 36, 40, 7, 39, 41, 15 ) );
print( ( newline ) );
SHOW fivenum( ( 15, 6, 42, 41, 7, 36, 49, 40, 39, 47, 43 ) );
print( ( newline ) );
SHOW fivenum( ( 0.14082834, 0.09748790, 1.73131507, 0.87636009
, -1.95059594, 0.73438555, -0.03035726, 1.46675970
, -0.74621349, -0.72588772, 0.63905160, 0.61501527
, -0.98983780, -1.00447874, -0.62759469, 0.66206163
, 1.04312009, -0.10305385, 0.75775634, 0.32566578
)
)
END
|
http://rosettacode.org/wiki/Forest_fire
|
Forest fire
|
This page uses content from Wikipedia. The original article was at Forest-fire model. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Task
Implement the Drossel and Schwabl definition of the forest-fire model.
It is basically a 2D cellular automaton where each cell can be in three distinct states (empty, tree and burning) and evolves according to the following rules (as given by Wikipedia)
A burning cell turns into an empty cell
A tree will burn if at least one neighbor is burning
A tree ignites with probability f even if no neighbor is burning
An empty space fills with a tree with probability p
Neighborhood is the Moore neighborhood; boundary conditions are so that on the boundary the cells are always empty ("fixed" boundary condition).
At the beginning, populate the lattice with empty and tree cells according to a specific probability (e.g. a cell has the probability 0.5 to be a tree). Then, let the system evolve.
Task's requirements do not include graphical display or the ability to change parameters (probabilities p and f ) through a graphical or command line interface.
Related tasks
See Conway's Game of Life
See Wireworld.
|
#Clojure
|
Clojure
|
(def burn-prob 0.1)
(def new-tree-prob 0.5)
(defn grow-new-tree? [] (> new-tree-prob (rand)))
(defn burn-tree? [] (> burn-prob (rand)))
(defn tree-maker [] (if (grow-new-tree?) :tree :grass))
(defn make-forest
([] (make-forest 5))
([size]
(take size (repeatedly #(take size (repeatedly tree-maker))))))
(defn tree-at [forest row col] (try (-> forest
(nth row)
(nth col))
(catch Exception _ false)))
(defn neighbores-burning? [forest row col]
(letfn [(burnt? [row col] (= :burnt (tree-at forest row col)))]
(or
(burnt? (inc row) col)
(burnt? (dec row) col)
(burnt? row (inc col))
(burnt? row (dec col)))))
(defn lightning-strike [forest]
(map (fn [forest-row]
(map #(if (and (= % :tree) (burn-tree?))
:fire!
%)
forest-row)
)
forest))
(defn burn-out-trees [forest]
(map (fn [forest-row]
(map #(case %
:burnt :grass
:fire! :burnt
%)
forest-row))
forest))
(defn burn-neighbores [forest]
(let [forest-size (count forest)
indicies (partition forest-size (for [row (range forest-size) col (range forest-size)] (cons row (list col))))]
(map (fn [forest-row indicies-row]
(map #(if (and
(= :tree %)
(neighbores-burning? forest (first %2) (second %2)))
:fire!
%)
forest-row indicies-row))
forest indicies)))
(defn grow-new-trees [forest] (map (fn [forest-row]
(map #(if (= % :grass)
(tree-maker)
%)
forest-row))
forest))
(defn forest-fire
([] (forest-fire 5))
([forest-size]
(loop
[forest (make-forest forest-size)]
(pprint forest)
(Thread/sleep 300)
(-> forest
(burn-out-trees)
(lightning-strike)
(burn-neighbores)
(grow-new-trees)
(recur)))))
(forest-fire)
|
http://rosettacode.org/wiki/Flatten_a_list
|
Flatten a list
|
Task
Write a function to flatten the nesting in an arbitrary list of values.
Your program should work on the equivalent of this list:
[[1], 2, [[3, 4], 5], [[[]]], [[[6]]], 7, 8, []]
Where the correct result would be the list:
[1, 2, 3, 4, 5, 6, 7, 8]
Related task
Tree traversal
|
#BQN
|
BQN
|
Enlist ← {(∾𝕊¨)⍟(1<≡)⥊𝕩}
|
http://rosettacode.org/wiki/Flipping_bits_game
|
Flipping bits game
|
The game
Given an N×N square array of zeroes or ones in an initial configuration, and a target configuration of zeroes and ones.
The game is to transform one to the other in as few moves as possible by inverting whole numbered rows or whole lettered
columns at once (as one move).
In an inversion. any 1 becomes 0, and any 0 becomes 1 for that whole row or column.
Task
Create a program to score for the Flipping bits game.
The game should create an original random target configuration and a starting configuration.
Ensure that the starting position is never the target position.
The target position must be guaranteed as reachable from the starting position. (One possible way to do this is to generate the start position by legal flips from a random target position. The flips will always be reversible back to the target from the given start position).
The number of moves taken so far should be shown.
Show an example of a short game here, on this page, for a 3×3 array of bits.
|
#Go
|
Go
|
package main
import (
"fmt"
"math/rand"
"time"
)
func main() {
rand.Seed(time.Now().UnixNano())
var n int = 3 // Change to define board size
var moves int = 0
a := make([][]int, n)
for i := range a {
a[i] = make([]int, n)
for j := range a {
a[i][j] = rand.Intn(2)
}
}
b := make([][]int, len(a))
for i := range a {
b[i] = make([]int, len(a[i]))
copy(b[i], a[i])
}
for i := rand.Intn(100); i > 0 || compareSlices(a, b) == true; i-- {
b = flipCol(b, rand.Intn(n) + 1)
b = flipRow(b, rand.Intn(n) + 1)
}
fmt.Println("Target:")
drawBoard(a)
fmt.Println("\nBoard:")
drawBoard(b)
var rc rune
var num int
for {
for{
fmt.Printf("\nFlip row (r) or column (c) 1 .. %d (c1, ...): ", n)
_, err := fmt.Scanf("%c%d", &rc, &num)
if err != nil {
fmt.Println(err)
continue
}
if num < 1 || num > n {
fmt.Println("Wrong command!")
continue
}
break
}
switch rc {
case 'c':
fmt.Printf("Column %v will be flipped\n", num)
flipCol(b, num)
case 'r':
fmt.Printf("Row %v will be flipped\n", num)
flipRow(b, num)
default:
fmt.Println("Wrong command!")
continue
}
moves++
fmt.Println("\nMoves taken: ", moves)
fmt.Println("Target:")
drawBoard(a)
fmt.Println("\nBoard:")
drawBoard(b)
if compareSlices(a, b) {
fmt.Printf("Finished. You win with %d moves!\n", moves)
break
}
}
}
func drawBoard (m [][]int) {
fmt.Print(" ")
for i := range m {
fmt.Printf("%d ", i+1)
}
for i := range m {
fmt.Println()
fmt.Printf("%d ", i+1)
for _, val := range m[i] {
fmt.Printf(" %d", val)
}
}
fmt.Print("\n")
}
func flipRow(m [][]int, row int) ([][]int) {
for j := range m {
m[row-1][j] ^= 1
}
return m
}
func flipCol(m [][]int, col int) ([][]int) {
for j := range m {
m[j][col-1] ^= 1
}
return m
}
func compareSlices(m [][]int, n[][]int) bool {
o := true
for i := range m {
for j := range m {
if m[i][j] != n[i][j] { o = false }
}
}
return o
}
|
http://rosettacode.org/wiki/First_power_of_2_that_has_leading_decimal_digits_of_12
|
First power of 2 that has leading decimal digits of 12
|
(This task is taken from a Project Euler problem.)
(All numbers herein are expressed in base ten.)
27 = 128 and 7 is
the first power of 2 whose leading decimal digits are 12.
The next power of 2 whose leading decimal digits
are 12 is 80,
280 = 1208925819614629174706176.
Define p(L,n) to be the nth-smallest
value of j such that the base ten representation
of 2j begins with the digits of L .
So p(12, 1) = 7 and
p(12, 2) = 80
You are also given that:
p(123, 45) = 12710
Task
find:
p(12, 1)
p(12, 2)
p(123, 45)
p(123, 12345)
p(123, 678910)
display the results here, on this page.
|
#C.23
|
C#
|
// a mini chrestomathy solution
using System;
class Program {
// translated from java example
static long js(int l, int n) {
long res = 0, f = 1;
double lf = Math.Log10(2);
for (int i = l; i > 10; i /= 10) f *= 10;
while (n > 0)
if ((int)(f * Math.Pow(10, ++res * lf % 1)) == l) n--;
return res;
}
// translated from go integer example (a.k.a. go translation of pascal alternative example)
static long gi(int ld, int n) {
string Ls = ld.ToString();
long res = 0, count = 0, f = 1;
for (int i = 1; i <= 18 - Ls.Length; i++) f *= 10;
const long ten18 = (long)1e18; long probe = 1;
do {
probe <<= 1; res++; if (probe >= ten18)
do {
if (probe >= ten18) probe /= 10;
if (probe / f == ld)
if (++count >= n) { count--; break; }
probe <<= 1; res++;
} while (true);
string ps = probe.ToString();
if (ps.Substring(0, Math.Min(Ls.Length, ps.Length)) == Ls)
if (++count >= n) break;
} while (true);
return res;
}
// translated from pascal alternative example
static long pa(int ld, int n) {
double L_float64 = Math.Pow(2, 64);
ulong Log10_2_64 = (ulong)(L_float64 * Math.Log10(2));
double Log10Num; ulong LmtUpper, LmtLower, Frac64;
long res = 0, dgts = 1, cnt;
for (int i = ld; i >= 10; i /= 10) dgts *= 10;
Log10Num = Math.Log10((ld + 1.0) / dgts);
// '316' was a limit
if (Log10Num >= 0.5) {
LmtUpper = (ld + 1.0) / dgts < 10.0 ? (ulong)(Log10Num * (L_float64 * 0.5)) * 2 + (ulong)(Log10Num * 2) : 0;
Log10Num = Math.Log10((double)ld / dgts);
LmtLower = (ulong)(Log10Num * (L_float64 * 0.5)) * 2 + (ulong)(Log10Num * 2);
} else {
LmtUpper = (ulong)(Log10Num * L_float64);
LmtLower = (ulong)(Math.Log10((double)ld / dgts) * L_float64);
}
cnt = 0; Frac64 = 0; if (LmtUpper != 0)
do {
res++; Frac64 += Log10_2_64;
if ((Frac64 >= LmtLower) & (Frac64 < LmtUpper))
if (++cnt >= n) break;
} while (true);
else // '999..'
do {
res++; Frac64 += Log10_2_64;
if (Frac64 >= LmtLower) if (++cnt >= n) break;
} while (true);
return res;
}
static int[] values = new int[] { 12, 1, 12, 2, 123, 45, 123, 12345, 123, 678910, 99, 1 };
static void doOne(string name, Func<int, int, long> fun) {
Console.WriteLine("{0} version:", name);
var start = DateTime.Now;
for (int i = 0; i < values.Length; i += 2)
Console.WriteLine("p({0,3}, {1,6}) = {2,11:n0}", values[i], values[i + 1], fun(values[i], values[i + 1]));
Console.WriteLine("Took {0} seconds\n", DateTime.Now - start);
}
static void Main() {
doOne("java simple", js);
doOne("go integer", gi);
doOne("pascal alternative", pa);
}
}
|
http://rosettacode.org/wiki/First-class_functions/Use_numbers_analogously
|
First-class functions/Use numbers analogously
|
In First-class functions, a language is showing how its manipulation of functions is similar to its manipulation of other types.
This tasks aim is to compare and contrast a language's implementation of first class functions, with its normal handling of numbers.
Write a program to create an ordered collection of a mixture of literally typed and expressions producing a real number, together with another ordered collection of their multiplicative inverses. Try and use the following pseudo-code to generate the numbers for the ordered collections:
x = 2.0
xi = 0.5
y = 4.0
yi = 0.25
z = x + y
zi = 1.0 / ( x + y )
Create a function multiplier, that given two numbers as arguments returns a function that when called with one argument, returns the result of multiplying the two arguments to the call to multiplier that created it and the argument in the call:
new_function = multiplier(n1,n2)
# where new_function(m) returns the result of n1 * n2 * m
Applying the multiplier of a number and its inverse from the two ordered collections of numbers in pairs, show that the result in each case is one.
Compare and contrast the resultant program with the corresponding entry in First-class functions. They should be close.
To paraphrase the task description: Do what was done before, but with numbers rather than functions
|
#Clojure
|
Clojure
|
(def x 2.0)
(def xi 0.5)
(def y 4.0)
(def yi 0.25)
(def z (+ x y))
(def zi (/ 1.0 (+ x y)))
(def numbers [x y z])
(def invers [xi yi zi])
(defn multiplier [a b]
(fn [m] (* a b m)))
> (for [[n i] (zipmap numbers invers)]
((multiplier n i) 0.5))
(0.5 0.5 0.5)
|
http://rosettacode.org/wiki/First-class_functions/Use_numbers_analogously
|
First-class functions/Use numbers analogously
|
In First-class functions, a language is showing how its manipulation of functions is similar to its manipulation of other types.
This tasks aim is to compare and contrast a language's implementation of first class functions, with its normal handling of numbers.
Write a program to create an ordered collection of a mixture of literally typed and expressions producing a real number, together with another ordered collection of their multiplicative inverses. Try and use the following pseudo-code to generate the numbers for the ordered collections:
x = 2.0
xi = 0.5
y = 4.0
yi = 0.25
z = x + y
zi = 1.0 / ( x + y )
Create a function multiplier, that given two numbers as arguments returns a function that when called with one argument, returns the result of multiplying the two arguments to the call to multiplier that created it and the argument in the call:
new_function = multiplier(n1,n2)
# where new_function(m) returns the result of n1 * n2 * m
Applying the multiplier of a number and its inverse from the two ordered collections of numbers in pairs, show that the result in each case is one.
Compare and contrast the resultant program with the corresponding entry in First-class functions. They should be close.
To paraphrase the task description: Do what was done before, but with numbers rather than functions
|
#Common_Lisp
|
Common Lisp
|
(defun multiplier (f g)
#'(lambda (x) (* f g x)))
(let* ((x 2.0)
(xi 0.5)
(y 4.0)
(yi 0.25)
(z (+ x y))
(zi (/ 1.0 (+ x y)))
(numbers (list x y z))
(inverses (list xi yi zi)))
(loop with value = 0.5
for number in numbers
for inverse in inverses
for multiplier = (multiplier number inverse)
do (format t "~&(~A * ~A)(~A) = ~A~%"
number
inverse
value
(funcall multiplier value))))
|
http://rosettacode.org/wiki/Flow-control_structures
|
Flow-control structures
|
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
Document common flow-control structures.
One common example of a flow-control structure is the goto construct.
Note that Conditional Structures and Loop Structures have their own articles/categories.
Related tasks
Conditional Structures
Loop Structures
|
#HicEst
|
HicEst
|
1 GOTO 2 ! branch to label
2 READ(FIle=name, IOStat=ios, ERror=3) something ! on error branch to label 3
3 ALARM(delay, n) ! n=2...9 simulate F2 to F9 keys: call asynchronously "Alarm"-SUBROUTINES F2...F9 with a delay
4 ALARM( 1 ) ! lets HicEst wait at this statement for any keyboard or mouse event
5 SYSTEM(WAIT=1000) ! msec
6 XEQ('CALL my_subroutine', *7) ! executes command string, on error branch to label 7
7 y = EXP(1E100, *8) ! on error branch to label 8
8 y = LOG( 0 , *9) ! on error branch to label 9
9 ALARM( 999 ) ! quit HicEst immediately
|
http://rosettacode.org/wiki/Flow-control_structures
|
Flow-control structures
|
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
Document common flow-control structures.
One common example of a flow-control structure is the goto construct.
Note that Conditional Structures and Loop Structures have their own articles/categories.
Related tasks
Conditional Structures
Loop Structures
|
#Icon_and_Unicon
|
Icon and Unicon
|
if x := every i := 1 to *container do { # * is the 'length' operator
if container[i] ~== y then
write("item ", i, " is not interesting")
else
break a
} then
write("found item ", x)
else
write("did not find an item")
|
http://rosettacode.org/wiki/Four_is_magic
|
Four is magic
|
Task
Write a subroutine, function, whatever it may be called in your language, that takes an integer number and returns an English text sequence starting with the English cardinal representation of that integer, the word 'is' and then the English cardinal representation of the count of characters that made up the first word, followed by a comma.
Continue the sequence by using the previous count word as the first word of the next phrase, append 'is' and the cardinal count of the letters in that word.
Continue until you reach four. Since four has four characters, finish by adding the words 'four is magic' and a period. All integers will eventually wind up at four.
For instance, suppose your are given the integer 3. Convert 3 to Three, add is , then the cardinal character count of three, or five, with a comma to separate if from the next phrase. Continue the sequence five is four, (five has four letters), and finally, four is magic.
Three is five, five is four, four is magic.
For reference, here are outputs for 0 through 9.
Zero is four, four is magic.
One is three, three is five, five is four, four is magic.
Two is three, three is five, five is four, four is magic.
Three is five, five is four, four is magic.
Four is magic.
Five is four, four is magic.
Six is three, three is five, five is four, four is magic.
Seven is five, five is four, four is magic.
Eight is five, five is four, four is magic.
Nine is four, four is magic.
Some task guidelines
You may assume the input will only contain integer numbers.
Cardinal numbers between 20 and 100 may use either hyphens or spaces as word separators but they must use a word separator. (23 is twenty three or twenty-three not twentythree.)
Cardinal number conversions should follow the English short scale. (billion is 1e9, trillion is 1e12, etc.)
Cardinal numbers should not include commas. (20140 is twenty thousand one hundred forty not twenty thousand, one hundred forty.)
When converted to a string, 100 should be one hundred, not a hundred or hundred, 1000 should be one thousand, not a thousand or thousand.
When converted to a string, there should be no and in the cardinal string. 130 should be one hundred thirty not one hundred and thirty.
When counting characters, count all of the characters in the cardinal number including spaces and hyphens. One hundred fifty-one should be 21 not 18.
The output should follow the format "N is K, K is M, M is ... four is magic." (unless the input is 4, in which case the output should simply be "four is magic.")
The output can either be the return value from the function, or be displayed from within the function.
You are encouraged, though not mandated to use proper sentence capitalization.
You may optionally support negative numbers. -7 is negative seven.
Show the output here for a small representative sample of values, at least 5 but no more than 25. You are free to choose which which numbers to use for output demonstration.
You can choose to use a library, (module, external routine, whatever) to do the cardinal conversions as long as the code is easily and freely available to the public.
If you roll your own, make the routine accept at minimum any integer from 0 up to 999999. If you use a pre-made library, support at least up to unsigned 64 bit integers. (or the largest integer supported in your language if it is less.)
Four is magic is a popular code-golf task. This is not code golf. Write legible, idiomatic and well formatted code.
Related tasks
Four is the number of_letters in the ...
Look-and-say sequence
Number names
Self-describing numbers
Summarize and say sequence
Spelling of ordinal numbers
De Bruijn sequences
|
#Rust
|
Rust
|
fn main() {
magic(4);
magic(2_340);
magic(765_000);
magic(27_000_001);
magic(999_123_090);
magic(239_579_832_723_441);
magic(std::u64::MAX);
}
fn magic(num: u64) {
if num == 4 {
println!("four is magic!");
println!();
return;
}
let name = number_name(num);
let len = name.len() as u64;
print!("{} is {}, ", name, number_name(len));
magic(len);
}
const LOW: &'static [&'static str] = &[
"zero", "one", "two", "three", "four", "five",
"six", "seven", "eight","nine", "ten",
"eleven", "twelve", "thirteen", "fourteen", "fifteen",
"sixteen", "seventeen", "eighteen", "nineteen"
];
const MED: &'static [&'static str] = &[
"twenty", "thirty", "forty", "fifty",
"sixy", "seventy", "eighty", "ninety"
];
const HIGH: &'static [&'static str] = &[
"thousand", "million", "billion",
"trillion", "quadrillion", "quintillion"
];
fn number_name(num: u64) -> String {
if num < 20 {
return LOW[num as usize].to_string();
}
if num < 100 {
let index = ((num / 10) - 2) as usize;
let tens = MED[index].to_string();
let remainder = num % 10;
if remainder > 0 {
return format!("{}-{}", tens, number_name(remainder));
}
return tens;
}
if num < 1000 {
let hundreds = LOW[(num / 100) as usize];
let remainder = num % 100;
if remainder > 0 {
return format!("{} hundred {}", hundreds, number_name(remainder));
}
return format!("{} hundred", hundreds);
}
let mut remainder = num % 1000;
let mut cur = if remainder > 0 { number_name(remainder) } else { "".to_string() };
let mut n = num / 1000;
for noun in HIGH.iter() {
if n > 0 {
remainder = n % 1000;
if remainder > 0 {
// this condition resolves double space issues
cur =
if cur.len() > 0 { format!("{} {} {}", number_name(remainder), noun, cur ) }
else { format!("{} {}", number_name(remainder), noun) }
}
n /= 1000;
}
}
return cur;
}
|
http://rosettacode.org/wiki/Four_is_magic
|
Four is magic
|
Task
Write a subroutine, function, whatever it may be called in your language, that takes an integer number and returns an English text sequence starting with the English cardinal representation of that integer, the word 'is' and then the English cardinal representation of the count of characters that made up the first word, followed by a comma.
Continue the sequence by using the previous count word as the first word of the next phrase, append 'is' and the cardinal count of the letters in that word.
Continue until you reach four. Since four has four characters, finish by adding the words 'four is magic' and a period. All integers will eventually wind up at four.
For instance, suppose your are given the integer 3. Convert 3 to Three, add is , then the cardinal character count of three, or five, with a comma to separate if from the next phrase. Continue the sequence five is four, (five has four letters), and finally, four is magic.
Three is five, five is four, four is magic.
For reference, here are outputs for 0 through 9.
Zero is four, four is magic.
One is three, three is five, five is four, four is magic.
Two is three, three is five, five is four, four is magic.
Three is five, five is four, four is magic.
Four is magic.
Five is four, four is magic.
Six is three, three is five, five is four, four is magic.
Seven is five, five is four, four is magic.
Eight is five, five is four, four is magic.
Nine is four, four is magic.
Some task guidelines
You may assume the input will only contain integer numbers.
Cardinal numbers between 20 and 100 may use either hyphens or spaces as word separators but they must use a word separator. (23 is twenty three or twenty-three not twentythree.)
Cardinal number conversions should follow the English short scale. (billion is 1e9, trillion is 1e12, etc.)
Cardinal numbers should not include commas. (20140 is twenty thousand one hundred forty not twenty thousand, one hundred forty.)
When converted to a string, 100 should be one hundred, not a hundred or hundred, 1000 should be one thousand, not a thousand or thousand.
When converted to a string, there should be no and in the cardinal string. 130 should be one hundred thirty not one hundred and thirty.
When counting characters, count all of the characters in the cardinal number including spaces and hyphens. One hundred fifty-one should be 21 not 18.
The output should follow the format "N is K, K is M, M is ... four is magic." (unless the input is 4, in which case the output should simply be "four is magic.")
The output can either be the return value from the function, or be displayed from within the function.
You are encouraged, though not mandated to use proper sentence capitalization.
You may optionally support negative numbers. -7 is negative seven.
Show the output here for a small representative sample of values, at least 5 but no more than 25. You are free to choose which which numbers to use for output demonstration.
You can choose to use a library, (module, external routine, whatever) to do the cardinal conversions as long as the code is easily and freely available to the public.
If you roll your own, make the routine accept at minimum any integer from 0 up to 999999. If you use a pre-made library, support at least up to unsigned 64 bit integers. (or the largest integer supported in your language if it is less.)
Four is magic is a popular code-golf task. This is not code golf. Write legible, idiomatic and well formatted code.
Related tasks
Four is the number of_letters in the ...
Look-and-say sequence
Number names
Self-describing numbers
Summarize and say sequence
Spelling of ordinal numbers
De Bruijn sequences
|
#Sidef
|
Sidef
|
func cardinal(n) {
static lingua_en = frequire("Lingua::EN::Numbers")
lingua_en.num2en(n) - / and|,/g
}
func four_is_magic(n) {
var str = ""
loop {
str += (cardinal(n) + " is ")
if (n == 4) {
str += "magic."
break
} else {
n = cardinal(n).len
str += (cardinal(n) + ", ")
}
}
str.tc
}
[0, 4, 6, 11, 13, 75, 337, -164, 9_876_543_209].each { |n|
say four_is_magic(n)
}
|
http://rosettacode.org/wiki/Floyd%27s_triangle
|
Floyd's triangle
|
Floyd's triangle lists the natural numbers in a right triangle aligned to the left where
the first row is 1 (unity)
successive rows start towards the left with the next number followed by successive naturals listing one more number than the line above.
The first few lines of a Floyd triangle looks like this:
1
2 3
4 5 6
7 8 9 10
11 12 13 14 15
Task
Write a program to generate and display here the first n lines of a Floyd triangle.
(Use n=5 and n=14 rows).
Ensure that when displayed in a mono-space font, the numbers line up in vertical columns as shown and that only one space separates numbers of the last row.
|
#Batch_File
|
Batch File
|
:: Floyd's triangle Task from Rosetta Code
:: Batch File Implementation
@echo off
rem main thing
setlocal enabledelayedexpansion
call :floydtriangle 5
echo(
call :floydtriangle 14
exit /b 0
:floydtriangle
set "fila=%1"
for /l %%c in (1,1,%fila%) do (
set /a "lastRowNum=%%c+fila*(fila-1)/2"
rem count number of digits of whole number trick
rem source: https://stackoverflow.com/a/45472269
set /a "Log=1!lastRowNum:~1!-!lastRowNum:~1!-0"
set /a "numColum[%%c]=!Log:0=+1!"
)
echo(Output for %fila%
set "thisNum=1"
for /l %%r in (1,1,%fila%) do (
set "printLine="
for /l %%c in (1,1,%%r) do (
rem count number of digits of whole number trick
set /a "Log=1!thisNum:~1!-!thisNum:~1!-0"
set /a "thisNumColum=!Log:0=+1!"
rem handle spacing
set "space= "
set /a "extra=!numColum[%%c]!-!thisNumColum!"
for /l %%s in (1,1,!extra!) do set "space=!space! "
rem append current number to printLine
set "printLine=!printLine!!space!!thisNum!"
set /a "thisNum=!thisNum!+1"
)
echo(!printLine!
)
goto :EOF
|
http://rosettacode.org/wiki/Floyd-Warshall_algorithm
|
Floyd-Warshall algorithm
|
The Floyd–Warshall algorithm is an algorithm for finding shortest paths in a weighted graph with positive or negative edge weights.
Task
Find the lengths of the shortest paths between all pairs of vertices of the given directed graph. Your code may assume that the input has already been checked for loops, parallel edges and negative cycles.
Print the pair, the distance and (optionally) the path.
Example
pair dist path
1 -> 2 -1 1 -> 3 -> 4 -> 2
1 -> 3 -2 1 -> 3
1 -> 4 0 1 -> 3 -> 4
2 -> 1 4 2 -> 1
2 -> 3 2 2 -> 1 -> 3
2 -> 4 4 2 -> 1 -> 3 -> 4
3 -> 1 5 3 -> 4 -> 2 -> 1
3 -> 2 1 3 -> 4 -> 2
3 -> 4 2 3 -> 4
4 -> 1 3 4 -> 2 -> 1
4 -> 2 -1 4 -> 2
4 -> 3 1 4 -> 2 -> 1 -> 3
See also
Floyd-Warshall Algorithm - step by step guide (youtube)
|
#Haskell
|
Haskell
|
import Control.Monad (join)
import Data.List (union)
import Data.Map hiding (foldr, union)
import Data.Maybe (fromJust, isJust)
import Data.Semigroup
import Prelude hiding (lookup, filter)
|
http://rosettacode.org/wiki/Function_definition
|
Function definition
|
A function is a body of code that returns a value.
The value returned may depend on arguments provided to the function.
Task
Write a definition of a function called "multiply" that takes two arguments and returns their product.
(Argument types should be chosen so as not to distract from showing how functions are created and values returned).
Related task
Function prototype
|
#Racket
|
Racket
|
(define (multiply a b) (* a b))
|
http://rosettacode.org/wiki/Function_definition
|
Function definition
|
A function is a body of code that returns a value.
The value returned may depend on arguments provided to the function.
Task
Write a definition of a function called "multiply" that takes two arguments and returns their product.
(Argument types should be chosen so as not to distract from showing how functions are created and values returned).
Related task
Function prototype
|
#Raku
|
Raku
|
sub multiply { return @_[0] * @_[1]; }
|
http://rosettacode.org/wiki/Forward_difference
|
Forward difference
|
Task
Provide code that produces a list of numbers which is the nth order forward difference, given a non-negative integer (specifying the order) and a list of numbers.
The first-order forward difference of a list of numbers A is a new list B, where Bn = An+1 - An.
List B should have one fewer element as a result.
The second-order forward difference of A will be:
tdefmodule Diff do
def forward(arr,i\\1) do
forward(arr,[],i)
end
def forward([_|[]],diffs,i) do
if i == 1 do
IO.inspect diffs
else
forward(diffs,[],i-1)
end
end
def forward([val1|[val2|vals]],diffs,i) do
forward([val2|vals],diffs++[val2-val1],i)
end
end
The same as the first-order forward difference of B.
That new list will have two fewer elements than A and one less than B.
The goal of this task is to repeat this process up to the desired order.
For a more formal description, see the related Mathworld article.
Algorithmic options
Iterate through all previous forward differences and re-calculate a new array each time.
Use this formula (from Wikipedia):
Δ
n
[
f
]
(
x
)
=
∑
k
=
0
n
(
n
k
)
(
−
1
)
n
−
k
f
(
x
+
k
)
{\displaystyle \Delta ^{n}[f](x)=\sum _{k=0}^{n}{n \choose k}(-1)^{n-k}f(x+k)}
(Pascal's Triangle may be useful for this option.)
|
#Lasso
|
Lasso
|
#!/usr/bin/lasso9
define forwardDiff(values, order::integer=1) => {
!#order ? return #values->asArray
local(result = array)
iterate(#values) => {
loop_count < #values->size ?
#result->insert(#values->get(loop_count+1) - #values->get(loop_count))
}
#order > 1 ? #result = forwardDiff(#result, #order-1)
return #result
}
local(data = (:90, 47, 58, 29, 22, 32, 55, 5, 55, 73))
with x in generateSeries(0, #data->size-1)
do stdoutnl(#x + ': ' + forwardDiff(#data, #x))
|
http://rosettacode.org/wiki/Forward_difference
|
Forward difference
|
Task
Provide code that produces a list of numbers which is the nth order forward difference, given a non-negative integer (specifying the order) and a list of numbers.
The first-order forward difference of a list of numbers A is a new list B, where Bn = An+1 - An.
List B should have one fewer element as a result.
The second-order forward difference of A will be:
tdefmodule Diff do
def forward(arr,i\\1) do
forward(arr,[],i)
end
def forward([_|[]],diffs,i) do
if i == 1 do
IO.inspect diffs
else
forward(diffs,[],i-1)
end
end
def forward([val1|[val2|vals]],diffs,i) do
forward([val2|vals],diffs++[val2-val1],i)
end
end
The same as the first-order forward difference of B.
That new list will have two fewer elements than A and one less than B.
The goal of this task is to repeat this process up to the desired order.
For a more formal description, see the related Mathworld article.
Algorithmic options
Iterate through all previous forward differences and re-calculate a new array each time.
Use this formula (from Wikipedia):
Δ
n
[
f
]
(
x
)
=
∑
k
=
0
n
(
n
k
)
(
−
1
)
n
−
k
f
(
x
+
k
)
{\displaystyle \Delta ^{n}[f](x)=\sum _{k=0}^{n}{n \choose k}(-1)^{n-k}f(x+k)}
(Pascal's Triangle may be useful for this option.)
|
#Logo
|
Logo
|
to fwd.diff :l
if empty? :l [output []]
if empty? bf :l [output []]
output fput (first bf :l)-(first :l) fwd.diff bf :l
end
to nth.fwd.diff :n :l
if :n = 0 [output :l]
output nth.fwd.diff :n-1 fwd.diff :l
end
show nth.fwd.diff 9 [90 47 58 29 22 32 55 5 55 73]
[-2921]
|
http://rosettacode.org/wiki/Hello_world/Text
|
Hello world/Text
|
Hello world/Text is part of Short Circuit's Console Program Basics selection.
Task
Display the string Hello world! on a text console.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello world/Newbie
Hello world/Newline omission
Hello world/Standard error
Hello world/Web server
|
#XPL0
|
XPL0
|
code Text=12;
Text(0, "Hello world!
")
|
http://rosettacode.org/wiki/Hello_world/Text
|
Hello world/Text
|
Hello world/Text is part of Short Circuit's Console Program Basics selection.
Task
Display the string Hello world! on a text console.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello world/Newbie
Hello world/Newline omission
Hello world/Standard error
Hello world/Web server
|
#XPath
|
XPath
|
'Hello world
'
|
http://rosettacode.org/wiki/Formatted_numeric_output
|
Formatted numeric output
|
Task
Express a number in decimal as a fixed-length string with leading zeros.
For example, the number 7.125 could be expressed as 00007.125.
|
#PHP
|
PHP
|
echo str_pad(7.125, 9, '0', STR_PAD_LEFT);
|
http://rosettacode.org/wiki/Four_bit_adder
|
Four bit adder
|
Task
"Simulate" a four-bit adder.
This design can be realized using four 1-bit full adders.
Each of these 1-bit full adders can be built with two half adders and an or gate. ;
Finally a half adder can be made using an xor gate and an and gate.
The xor gate can be made using two nots, two ands and one or.
Not, or and and, the only allowed "gates" for the task, can be "imitated" by using the bitwise operators of your language.
If there is not a bit type in your language, to be sure that the not does not "invert" all the other bits of the basic type (e.g. a byte) we are not interested in, you can use an extra nand (and then not) with the constant 1 on one input.
Instead of optimizing and reducing the number of gates used for the final 4-bit adder, build it in the most straightforward way, connecting the other "constructive blocks", in turn made of "simpler" and "smaller" ones.
Schematics of the "constructive blocks"
(Xor gate with ANDs, ORs and NOTs)
(A half adder)
(A full adder)
(A 4-bit adder)
Solutions should try to be as descriptive as possible, making it as easy as possible to identify "connections" between higher-order "blocks".
It is not mandatory to replicate the syntax of higher-order blocks in the atomic "gate" blocks, i.e. basic "gate" operations can be performed as usual bitwise operations, or they can be "wrapped" in a block in order to expose the same syntax of higher-order blocks, at implementers' choice.
To test the implementation, show the sum of two four-bit numbers (in binary).
|
#Mathematica_.2F_Wolfram_Language
|
Mathematica / Wolfram Language
|
and[a_, b_] := Max[a, b];
or[a_, b_] := Min[a, b];
not[a_] := 1 - a;
xor[a_, b_] := or[and[a, not[b]], and[b, not[a]]];
halfadder[a_, b_] := {xor[a, b], and[a, b]};
fulladder[a_, b_, c0_] := Module[{s, c, c1},
{s, c} = halfadder[c0, a];
{s, c1} = halfadder[s, b];
{s, or[c, c1]}];
fourbitadder[{a3_, a2_, a1_, a0_}, {b3_, b2_, b1_, b0_}] :=
Module[{s0, s1, s2, s3, c0, c1, c2, c3},
{s0, c0} = fulladder[a0, b0, 0];
{s1, c1} = fulladder[a1, b1, c0];
{s2, c2} = fulladder[a2, b2, c1];
{s3, c3} = fulladder[a3, b3, c2];
{{s3, s2, s1, s0}, c3}];
|
http://rosettacode.org/wiki/Fivenum
|
Fivenum
|
Many big data or scientific programs use boxplots to show distributions of data. In addition, sometimes saving large arrays for boxplots can be impractical and use extreme amounts of RAM. It can be useful to save large arrays as arrays with five numbers to save memory.
For example, the R programming language implements Tukey's five-number summary as the fivenum function.
Task
Given an array of numbers, compute the five-number summary.
Note
While these five numbers can be used to draw a boxplot, statistical packages will typically need extra data.
Moreover, while there is a consensus about the "box" of the boxplot, there are variations among statistical packages for the whiskers.
|
#AppleScript
|
AppleScript
|
use AppleScript version "2.4" -- Mac OS X 10.10. (Yosemite) or later.
use framework "Foundation"
on fivenum(listOfNumbers, l, r)
script o
property lst : missing value
on medianFromRange(l, r)
set m1 to (l + r) div 2
set m2 to m1 + (l + r) mod 2
set median to my lst's item m1
if (m2 > m1) then set median to (median + (my lst's item m2)) / 2
return {median, m1, m2}
end medianFromRange
end script
if ((listOfNumbers is {}) or (r - l < 0)) then return missing value
set o's lst to current application's class "NSMutableArray"'s arrayWithArray:(listOfNumbers)
tell o's lst to sortUsingSelector:("compare:")
set o's lst to o's lst as list
set {median, m1, m2} to o's medianFromRange(l, r)
set {lowerQuartile} to o's medianFromRange(l, m1)
set {upperQuartile} to o's medianFromRange(m2, r)
return {o's lst's beginning, lowerQuartile, median, upperQuartile, o's lst's end}
end fivenum
-- Test code:
set x to {15, 6, 42, 41, 7, 36, 49, 40, 39, 47, 43}
set y to {36, 40, 7, 39, 41, 15}
set z to {0.14082834, 0.0974879, 1.73131507, 0.87636009, -1.95059594, 0.73438555, -0.03035726, 1.4667597, -0.74621349, -0.72588772, ¬
0.6390516, 0.61501527, -0.9898378, -1.00447874, -0.62759469, 0.66206163, 1.04312009, -0.10305385, 0.75775634, 0.32566578}
return {fivenum(x, 1, count x), fivenum(y, 1, count y), fivenum(z, 1, count z)}
|
http://rosettacode.org/wiki/Forest_fire
|
Forest fire
|
This page uses content from Wikipedia. The original article was at Forest-fire model. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Task
Implement the Drossel and Schwabl definition of the forest-fire model.
It is basically a 2D cellular automaton where each cell can be in three distinct states (empty, tree and burning) and evolves according to the following rules (as given by Wikipedia)
A burning cell turns into an empty cell
A tree will burn if at least one neighbor is burning
A tree ignites with probability f even if no neighbor is burning
An empty space fills with a tree with probability p
Neighborhood is the Moore neighborhood; boundary conditions are so that on the boundary the cells are always empty ("fixed" boundary condition).
At the beginning, populate the lattice with empty and tree cells according to a specific probability (e.g. a cell has the probability 0.5 to be a tree). Then, let the system evolve.
Task's requirements do not include graphical display or the ability to change parameters (probabilities p and f ) through a graphical or command line interface.
Related tasks
See Conway's Game of Life
See Wireworld.
|
#COBOL
|
COBOL
|
IDENTIFICATION DIVISION.
PROGRAM-ID. forest-fire.
DATA DIVISION.
WORKING-STORAGE SECTION.
*> Probability represents a fraction of 10000.
*> For instance, IGNITE-PROB means a tree has a 1 in 10000 chance
*> of igniting.
78 IGNITE-PROB VALUE 1.
78 NEW-TREE-PROB VALUE 100.
78 EMPTY-PROB VALUE 3333.
78 AREA-SIZE VALUE 40.
01 sim-table.
03 sim-row OCCURS AREA-SIZE TIMES INDEXED BY row-index.
05 sim-area OCCURS AREA-SIZE TIMES
INDEXED BY col-index.
07 current-status PIC 9.
*> The flags correspond to the colours they will
*> be displayed as.
88 empty VALUE 0. *> Black
88 tree VALUE 2. *> Green
88 burning VALUE 4. *> Red
07 next-status PIC 9.
88 empty VALUE 0.
88 tree VALUE 2.
88 burning VALUE 4.
01 rand-num PIC 9999.
01 next-row PIC 9(4).
01 next-col PIC 9(4).
01 neighbours-row PIC 9(4).
01 neighbours-col PIC 9(4).
PROCEDURE DIVISION.
main-line.
*> Seed RANDOM with current time.
MOVE FUNCTION RANDOM(FUNCTION CURRENT-DATE (9:8)) TO rand-num
PERFORM initialise-table
PERFORM FOREVER
PERFORM show-simulation
PERFORM step-simulation
END-PERFORM
GOBACK
.
initialise-table.
PERFORM VARYING row-index FROM 1 BY 1
UNTIL AREA-SIZE < row-index
AFTER col-index FROM 1 BY 1
UNTIL AREA-SIZE < col-index
PERFORM get-rand-num
IF rand-num <= EMPTY-PROB
SET empty OF current-status (row-index, col-index)
TO TRUE
SET empty OF next-status (row-index, col-index)
TO TRUE
ELSE
SET tree OF current-status (row-index, col-index)
TO TRUE
SET tree OF next-status (row-index, col-index)
TO TRUE
END-IF
END-PERFORM
.
show-simulation.
PERFORM VARYING row-index FROM 1 BY 1
UNTIL AREA-SIZE < row-index
AFTER col-index FROM 1 BY 1
UNTIL AREA-SIZE < col-index
DISPLAY SPACE AT LINE row-index COLUMN col-index
WITH BACKGROUND-COLOR
current-status (row-index, col-index)
END-PERFORM
.
*> Updates the simulation.
step-simulation.
PERFORM VARYING row-index FROM 1 BY 1
UNTIL AREA-SIZE < row-index
AFTER col-index FROM 1 BY 1
UNTIL AREA-SIZE < col-index
EVALUATE TRUE
WHEN empty OF current-status (row-index, col-index)
PERFORM get-rand-num
IF rand-num <= NEW-TREE-PROB
SET tree OF next-status
(row-index, col-index) TO TRUE
END-IF
WHEN tree OF current-status (row-index, col-index)
PERFORM simulate-tree
WHEN burning OF current-status
(row-index, col-index)
SET empty OF next-status (row-index, col-index)
TO TRUE
END-EVALUATE
END-PERFORM
PERFORM update-statuses.
.
*> Updates a tree tile, assuming row-index and col-index are at
*> a tree area.
simulate-tree.
*> Find the row and column of the bottom-right neighbour.
COMPUTE next-row = FUNCTION MIN(row-index + 1, AREA-SIZE)
COMPUTE next-col = FUNCTION MIN(col-index + 1, AREA-SIZE)
COMPUTE neighbours-row = FUNCTION MAX(row-index - 1, 1)
COMPUTE neighbours-col = FUNCTION MAX(col-index - 1, 1)
*> If a neighbour is burning, catch fire.
PERFORM VARYING neighbours-row FROM neighbours-row BY 1
UNTIL next-row < neighbours-row
*> Check if neighbours in a row are on fire.
PERFORM VARYING neighbours-col FROM neighbours-col BY 1
UNTIL next-col < neighbours-col
IF neighbours-row = row-index
AND neighbours-col = col-index
EXIT PERFORM CYCLE
END-IF
IF burning OF current-status
(neighbours-row, neighbours-col)
SET burning OF next-status (row-index, col-index)
TO TRUE
EXIT PARAGRAPH
END-IF
END-PERFORM
*> Move neighbours-col back to starting position
COMPUTE neighbours-col =
FUNCTION MAX(neighbours-col - 3, 1)
END-PERFORM
*> Otherwise, there is a random chance of
*> catching fire.
PERFORM get-rand-num
IF rand-num <= IGNITE-PROB
SET burning OF next-status (row-index, col-index) TO TRUE
END-IF
.
update-statuses.
PERFORM VARYING row-index FROM 1 BY 1
UNTIL AREA-SIZE < row-index
AFTER col-index FROM 1 BY 1
UNTIL AREA-SIZE < col-index
MOVE next-status (row-index, col-index)
TO current-status (row-index, col-index)
END-PERFORM
.
*> Puts a random value between 0 and 9999 in rand-num.
get-rand-num.
COMPUTE rand-num =
FUNCTION MOD(FUNCTION RANDOM * 100000, 10000)
.
|
http://rosettacode.org/wiki/Flatten_a_list
|
Flatten a list
|
Task
Write a function to flatten the nesting in an arbitrary list of values.
Your program should work on the equivalent of this list:
[[1], 2, [[3, 4], 5], [[[]]], [[[6]]], 7, 8, []]
Where the correct result would be the list:
[1, 2, 3, 4, 5, 6, 7, 8]
Related task
Tree traversal
|
#Bracmat
|
Bracmat
|
( (myList = ((1), 2, ((3,4), 5), ((())), (((6))), 7, 8, ()))
& put$("Unevaluated:")
& lst$myList
& !myList:?myList { the expression !myList evaluates myList }
& put$("Flattened:")
& lst$myList
)
|
http://rosettacode.org/wiki/Flipping_bits_game
|
Flipping bits game
|
The game
Given an N×N square array of zeroes or ones in an initial configuration, and a target configuration of zeroes and ones.
The game is to transform one to the other in as few moves as possible by inverting whole numbered rows or whole lettered
columns at once (as one move).
In an inversion. any 1 becomes 0, and any 0 becomes 1 for that whole row or column.
Task
Create a program to score for the Flipping bits game.
The game should create an original random target configuration and a starting configuration.
Ensure that the starting position is never the target position.
The target position must be guaranteed as reachable from the starting position. (One possible way to do this is to generate the start position by legal flips from a random target position. The flips will always be reversible back to the target from the given start position).
The number of moves taken so far should be shown.
Show an example of a short game here, on this page, for a 3×3 array of bits.
|
#Haskell
|
Haskell
|
import Data.List (intersperse)
import System.Random (randomRIO)
import Data.Array (Array, (!), (//), array, bounds)
import Control.Monad (zipWithM_, replicateM, foldM, when)
type Board = Array (Char, Char) Int
flp :: Int -> Int
flp 0 = 1
flp 1 = 0
numRows, numCols :: Board -> String
numRows t =
let ((a, _), (b, _)) = bounds t
in [a .. b]
numCols t =
let ((_, a), (_, b)) = bounds t
in [a .. b]
flipRow, flipCol :: Board -> Char -> Board
flipRow t r =
let e =
[ (ix, flp (t ! ix))
| ix <- zip (repeat r) (numCols t) ]
in t // e
flipCol t c =
let e =
[ (ix, flp (t ! ix))
| ix <- zip (numRows t) (repeat c) ]
in t // e
printBoard :: Board -> IO ()
printBoard t = do
let rows = numRows t
cols = numCols t
f 0 = '0'
f 1 = '1'
p r xs = putStrLn $ [r, ' '] ++ intersperse ' ' (map f xs)
putStrLn $ " " ++ intersperse ' ' cols
zipWithM_
p
rows
[ [ t ! (y, x)
| x <- cols ]
| y <- rows ]
-- create a random goal board, and flip rows and columns randomly
-- to get a starting board
setupGame :: Char -> Char -> IO (Board, Board)
setupGame sizey sizex
-- random cell value at (row, col)
= do
let mk rc = (\v -> (rc, v)) <$> randomRIO (0, 1)
rows = ['a' .. sizey]
cols = ['1' .. sizex]
goal <-
array (('a', '1'), (sizey, sizex)) <$>
mapM
mk
[ (r, c)
| r <- rows
, c <- cols ]
start <-
do let change :: Board -> Int -> IO Board
-- flip random row
change t 0 = flipRow t <$> randomRIO ('a', sizey)
-- flip random col
change t 1 = flipCol t <$> randomRIO ('1', sizex)
numMoves <- randomRIO (3, 15) -- how many flips (3 - 15)
-- determine if rows or cols are flipped
moves <- replicateM numMoves $ randomRIO (0, 1)
-- make changes and get a starting board
foldM change goal moves
if goal /= start -- check if boards are different
then return (goal, start) -- all ok, return both boards
else setupGame sizey sizex -- try again
main :: IO ()
main = do
putStrLn "Select a board size (1 - 9).\nPress any other key to exit."
sizec <- getChar
when (sizec `elem` ['1' .. '9']) $
do let size = read [sizec] - 1
(g, s) <- setupGame (['a' ..] !! size) (['1' ..] !! size)
turns g s 0
where
turns goal current moves = do
putStrLn "\nGoal:"
printBoard goal
putStrLn "\nBoard:"
printBoard current
when (moves > 0) $
putStrLn $ "\nYou've made " ++ show moves ++ " moves so far."
putStrLn $
"\nFlip a row (" ++
numRows current ++ ") or a column (" ++ numCols current ++ ")"
v <- getChar
if v `elem` numRows current
then check $ flipRow current v
else if v `elem` numCols current
then check $ flipCol current v
else tryAgain
where
check t =
if t == goal
then putStrLn $ "\nYou've won in " ++ show (moves + 1) ++ " moves!"
else turns goal t (moves + 1)
tryAgain = do
putStrLn ": Invalid row or column."
turns goal current moves
|
http://rosettacode.org/wiki/First_power_of_2_that_has_leading_decimal_digits_of_12
|
First power of 2 that has leading decimal digits of 12
|
(This task is taken from a Project Euler problem.)
(All numbers herein are expressed in base ten.)
27 = 128 and 7 is
the first power of 2 whose leading decimal digits are 12.
The next power of 2 whose leading decimal digits
are 12 is 80,
280 = 1208925819614629174706176.
Define p(L,n) to be the nth-smallest
value of j such that the base ten representation
of 2j begins with the digits of L .
So p(12, 1) = 7 and
p(12, 2) = 80
You are also given that:
p(123, 45) = 12710
Task
find:
p(12, 1)
p(12, 2)
p(123, 45)
p(123, 12345)
p(123, 678910)
display the results here, on this page.
|
#D
|
D
|
import std.math;
import std.stdio;
int p(int l, int n) {
int test = 0;
double logv = log(2.0) / log(10.0);
int factor = 1;
int loop = l;
while (loop > 10) {
factor *= 10;
loop /= 10;
}
while (n > 0) {
int val;
test++;
val = cast(int)(factor * pow(10.0, fmod(test * logv, 1)));
if (val == l) {
n--;
}
}
return test;
}
void runTest(int l, int n) {
writefln("p(%d, %d) = %d", l, n, p(l, n));
}
void main() {
runTest(12, 1);
runTest(12, 2);
runTest(123, 45);
runTest(123, 12345);
runTest(123, 678910);
}
|
http://rosettacode.org/wiki/First-class_functions/Use_numbers_analogously
|
First-class functions/Use numbers analogously
|
In First-class functions, a language is showing how its manipulation of functions is similar to its manipulation of other types.
This tasks aim is to compare and contrast a language's implementation of first class functions, with its normal handling of numbers.
Write a program to create an ordered collection of a mixture of literally typed and expressions producing a real number, together with another ordered collection of their multiplicative inverses. Try and use the following pseudo-code to generate the numbers for the ordered collections:
x = 2.0
xi = 0.5
y = 4.0
yi = 0.25
z = x + y
zi = 1.0 / ( x + y )
Create a function multiplier, that given two numbers as arguments returns a function that when called with one argument, returns the result of multiplying the two arguments to the call to multiplier that created it and the argument in the call:
new_function = multiplier(n1,n2)
# where new_function(m) returns the result of n1 * n2 * m
Applying the multiplier of a number and its inverse from the two ordered collections of numbers in pairs, show that the result in each case is one.
Compare and contrast the resultant program with the corresponding entry in First-class functions. They should be close.
To paraphrase the task description: Do what was done before, but with numbers rather than functions
|
#D
|
D
|
import std.stdio;
auto multiplier(double a, double b)
{
return (double c) => a * b * c;
}
void main()
{
double x = 2.0;
double xi = 0.5;
double y = 4.0;
double yi = 0.25;
double z = x + y;
double zi = 1.0 / (z);
double[3] f = [x, y, z];
double[3] r = [xi, yi, zi];
foreach (i; 0..3)
{
auto mult = multiplier(f[i], r[i]);
writefln("%f * %f * %f == %f", f[i], r[i], 1.0, mult(1));
}
}
|
http://rosettacode.org/wiki/First-class_functions/Use_numbers_analogously
|
First-class functions/Use numbers analogously
|
In First-class functions, a language is showing how its manipulation of functions is similar to its manipulation of other types.
This tasks aim is to compare and contrast a language's implementation of first class functions, with its normal handling of numbers.
Write a program to create an ordered collection of a mixture of literally typed and expressions producing a real number, together with another ordered collection of their multiplicative inverses. Try and use the following pseudo-code to generate the numbers for the ordered collections:
x = 2.0
xi = 0.5
y = 4.0
yi = 0.25
z = x + y
zi = 1.0 / ( x + y )
Create a function multiplier, that given two numbers as arguments returns a function that when called with one argument, returns the result of multiplying the two arguments to the call to multiplier that created it and the argument in the call:
new_function = multiplier(n1,n2)
# where new_function(m) returns the result of n1 * n2 * m
Applying the multiplier of a number and its inverse from the two ordered collections of numbers in pairs, show that the result in each case is one.
Compare and contrast the resultant program with the corresponding entry in First-class functions. They should be close.
To paraphrase the task description: Do what was done before, but with numbers rather than functions
|
#E
|
E
|
def x := 2.0
def xi := 0.5
def y := 4.0
def yi := 0.25
def z := x + y
def zi := 1.0 / (x + y)
def forward := [x, y, z ]
def reverse := [xi, yi, zi]
def multiplier(a, b) {
return fn x { a * b * x }
}
def s := 0.5
for i => a in forward {
def b := reverse[i]
println(`s = $s, a = $a, b = $b, multiplier($a, $b)($s) = ${multiplier(a, b)(s)}`)
}
|
http://rosettacode.org/wiki/Flow-control_structures
|
Flow-control structures
|
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
Document common flow-control structures.
One common example of a flow-control structure is the goto construct.
Note that Conditional Structures and Loop Structures have their own articles/categories.
Related tasks
Conditional Structures
Loop Structures
|
#IDL
|
IDL
|
test:
..some code here
goto, test
|
http://rosettacode.org/wiki/Flow-control_structures
|
Flow-control structures
|
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
Document common flow-control structures.
One common example of a flow-control structure is the goto construct.
Note that Conditional Structures and Loop Structures have their own articles/categories.
Related tasks
Conditional Structures
Loop Structures
|
#J
|
J
|
2 * 1 2 3
2 4 6
|
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