task_url
stringlengths
30
116
task_name
stringlengths
2
86
task_description
stringlengths
0
14.4k
language_url
stringlengths
2
53
language_name
stringlengths
1
52
code
stringlengths
0
61.9k
http://rosettacode.org/wiki/System_time
System time
Task Output the system time   (any units will do as long as they are noted) either by a system command or one built into the language. The system time can be used for debugging, network information, random number seeds, or something as simple as program performance. Related task   Date format See also   Retrieving system time (wiki)
#NetRexx
NetRexx
  import java.text.SimpleDateFormat say SimpleDateFormat("yyyy-MM-dd-HH.mm.ss.SSS").format(Date())
http://rosettacode.org/wiki/Sum_of_elements_below_main_diagonal_of_matrix
Sum of elements below main diagonal of matrix
Task Find and display the sum of elements that are below the main diagonal of a matrix. The matrix should be a square matrix. ───   Matrix to be used:   ─── [[1,3,7,8,10], [2,4,16,14,4], [3,1,9,18,11], [12,14,17,18,20], [7,1,3,9,5]]
#AutoHotkey
AutoHotkey
matrx :=[[1,3,7,8,10] ,[2,4,16,14,4] ,[3,1,9,18,11] ,[12,14,17,18,20] ,[7,1,3,9,5]] sumA := sumB := sumD := sumAll := 0 for r, obj in matrx for c, val in obj sumAll += val ,sumA += r<c ? val : 0 ,sumB += r>c ? val : 0 ,sumD += r=c ? val : 0   MsgBox % result := "sum above diagonal = " sumA . "`nsum below diagonal = " sumB . "`nsum on diagonal = " sumD . "`nsum all = " sumAll
http://rosettacode.org/wiki/Sum_of_elements_below_main_diagonal_of_matrix
Sum of elements below main diagonal of matrix
Task Find and display the sum of elements that are below the main diagonal of a matrix. The matrix should be a square matrix. ───   Matrix to be used:   ─── [[1,3,7,8,10], [2,4,16,14,4], [3,1,9,18,11], [12,14,17,18,20], [7,1,3,9,5]]
#AWK
AWK
  # syntax: GAWK -f SUM_OF_ELEMENTS_BELOW_MAIN_DIAGONAL_OF_MATRIX.AWK BEGIN { arr1[++n] = "1,3,7,8,10" arr1[++n] = "2,4,16,14,4" arr1[++n] = "3,1,9,18,11" arr1[++n] = "12,14,17,18,20" arr1[++n] = "7,1,3,9,5" for (i=1; i<=n; i++) { x = split(arr1[i],arr2,",") if (x != n) { printf("error: row %d has %d elements; S/B %d\n",i,x,n) errors++ continue } for (j=1; j<i; j++) { # below main diagonal sum_b += arr2[j] cnt_b++ } for (j=i+1; j<=n; j++) { # above main diagonal sum_a += arr2[j] cnt_a++ } for (j=1; j<=i; j++) { # on main diagonal if (j == i) { sum_o += arr2[j] cnt_o++ } } } if (errors > 0) { exit(1) } printf("%5g Sum of the %d elements below main diagonal\n",sum_b,cnt_b) printf("%5g Sum of the %d elements above main diagonal\n",sum_a,cnt_a) printf("%5g Sum of the %d elements on main diagonal\n",sum_o,cnt_o) printf("%5g Sum of the %d elements in the matrix\n",sum_b+sum_a+sum_o,cnt_b+cnt_a+cnt_o) exit(0) }  
http://rosettacode.org/wiki/Symmetric_difference
Symmetric difference
Task Given two sets A and B, compute ( A ∖ B ) ∪ ( B ∖ A ) . {\displaystyle (A\setminus B)\cup (B\setminus A).} That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B. In other words: ( A ∪ B ) ∖ ( A ∩ B ) {\displaystyle (A\cup B)\setminus (A\cap B)} (the set of items that are in at least one of A or B minus the set of items that are in both A and B). Optionally, give the individual differences ( A ∖ B {\displaystyle A\setminus B} and B ∖ A {\displaystyle B\setminus A} ) as well. Test cases A = {John, Bob, Mary, Serena} B = {Jim, Mary, John, Bob} Notes If your code uses lists of items to represent sets then ensure duplicate items in lists are correctly handled. For example two lists representing sets of a = ["John", "Serena", "Bob", "Mary", "Serena"] and b = ["Jim", "Mary", "John", "Jim", "Bob"] should produce the result of just two strings: ["Serena", "Jim"], in any order. In the mathematical notation above A \ B gives the set of items in A that are not in B; A ∪ B gives the set of items in both A and B, (their union); and A ∩ B gives the set of items that are in both A and B (their intersection).
#Racket
Racket
  #lang racket (define A (set "John" "Bob" "Mary" "Serena")) (define B (set "Jim" "Mary" "John" "Bob"))   (set-symmetric-difference A B) (set-subtract A B) (set-subtract B A)  
http://rosettacode.org/wiki/Symmetric_difference
Symmetric difference
Task Given two sets A and B, compute ( A ∖ B ) ∪ ( B ∖ A ) . {\displaystyle (A\setminus B)\cup (B\setminus A).} That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B. In other words: ( A ∪ B ) ∖ ( A ∩ B ) {\displaystyle (A\cup B)\setminus (A\cap B)} (the set of items that are in at least one of A or B minus the set of items that are in both A and B). Optionally, give the individual differences ( A ∖ B {\displaystyle A\setminus B} and B ∖ A {\displaystyle B\setminus A} ) as well. Test cases A = {John, Bob, Mary, Serena} B = {Jim, Mary, John, Bob} Notes If your code uses lists of items to represent sets then ensure duplicate items in lists are correctly handled. For example two lists representing sets of a = ["John", "Serena", "Bob", "Mary", "Serena"] and b = ["Jim", "Mary", "John", "Jim", "Bob"] should produce the result of just two strings: ["Serena", "Jim"], in any order. In the mathematical notation above A \ B gives the set of items in A that are not in B; A ∪ B gives the set of items in both A and B, (their union); and A ∩ B gives the set of items that are in both A and B (their intersection).
#Raku
Raku
my \A = set <John Serena Bob Mary Serena>; my \B = set <Jim Mary John Jim Bob>;   say A ∖ B; # Set subtraction say B ∖ A; # Set subtraction say (A ∪ B) ∖ (A ∩ B); # Symmetric difference, via basic set operations say A ⊖ B; # Symmetric difference, via dedicated operator
http://rosettacode.org/wiki/Temperature_conversion
Temperature conversion
There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones: Kelvin, Celsius, Fahrenheit, and Rankine. The Celsius and Kelvin scales have the same magnitude, but different null points. 0 degrees Celsius corresponds to 273.15 kelvin. 0 kelvin is absolute zero. The Fahrenheit and Rankine scales also have the same magnitude, but different null points. 0 degrees Fahrenheit corresponds to 459.67 degrees Rankine. 0 degrees Rankine is absolute zero. The Celsius/Kelvin and Fahrenheit/Rankine scales have a ratio of 5 : 9. Task Write code that accepts a value of kelvin, converts it to values of the three other scales, and prints the result. Example K 21.00 C -252.15 F -421.87 R 37.80
#PARI.2FGP
PARI/GP
f(x)=[x,x-273.15,1.8*x-459.67,1.8*x]
http://rosettacode.org/wiki/Temperature_conversion
Temperature conversion
There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones: Kelvin, Celsius, Fahrenheit, and Rankine. The Celsius and Kelvin scales have the same magnitude, but different null points. 0 degrees Celsius corresponds to 273.15 kelvin. 0 kelvin is absolute zero. The Fahrenheit and Rankine scales also have the same magnitude, but different null points. 0 degrees Fahrenheit corresponds to 459.67 degrees Rankine. 0 degrees Rankine is absolute zero. The Celsius/Kelvin and Fahrenheit/Rankine scales have a ratio of 5 : 9. Task Write code that accepts a value of kelvin, converts it to values of the three other scales, and prints the result. Example K 21.00 C -252.15 F -421.87 R 37.80
#Pascal
Pascal
program TemperatureConvert;   type TemperatureType = (C, F, K, R);   var kelvin: real;   function ConvertTemperature(temperature: real; fromType, toType: TemperatureType): real;   var initial, result: real;   begin (* We are going to first convert whatever we're given into Celsius. Then we'll convert that into whatever we're asked to convert into. Maybe not the most efficient way to do this, but easy to understand and should make it easier to add any additional temperature units. *) if fromType <> toType then begin case fromType of (* first convert the temperature into Celsius *) C: initial := temperature; F: initial := (temperature - 32) / 1.8; K: initial := temperature - 273.15; R: initial := (temperature - 491.67) / 1.8; end; case toType of (* now convert from Celsius into whatever degree type was asked for *) C: result := initial; F: result := (initial * 1.8) + 32; K: result := initial + 273.15; R: result := (initial * 1.8) + 491.67; end; end else (* no point doing all that math if we're asked to convert from and to the same type *) result := temperature; ConvertTemperature := result; end;   begin write('Temperature to convert (in kelvins): '); readln(kelvin); writeln(kelvin : 3 : 2, ' in kelvins is '); writeln(' ', ConvertTemperature(kelvin, K, C) : 3 : 2, ' in degrees Celsius.'); writeln(' ', ConvertTemperature(kelvin, K, F) : 3 : 2, ' in degrees Fahrenheit.'); writeln(' ', ConvertTemperature(kelvin, K, R) : 3 : 2, ' in degrees Rankine.'); end.
http://rosettacode.org/wiki/System_time
System time
Task Output the system time   (any units will do as long as they are noted) either by a system command or one built into the language. The system time can be used for debugging, network information, random number seeds, or something as simple as program performance. Related task   Date format See also   Retrieving system time (wiki)
#NewLISP
NewLISP
> (date) "Sun Sep 28 20:17:55 2014"
http://rosettacode.org/wiki/System_time
System time
Task Output the system time   (any units will do as long as they are noted) either by a system command or one built into the language. The system time can be used for debugging, network information, random number seeds, or something as simple as program performance. Related task   Date format See also   Retrieving system time (wiki)
#Nim
Nim
import times   echo getDateStr() echo getClockStr() echo getTime() echo now() # shorthand for "getTime().local"
http://rosettacode.org/wiki/Sum_of_elements_below_main_diagonal_of_matrix
Sum of elements below main diagonal of matrix
Task Find and display the sum of elements that are below the main diagonal of a matrix. The matrix should be a square matrix. ───   Matrix to be used:   ─── [[1,3,7,8,10], [2,4,16,14,4], [3,1,9,18,11], [12,14,17,18,20], [7,1,3,9,5]]
#BASIC
BASIC
arraybase 1 dim diag = {{ 1, 3, 7, 8,10}, { 2, 4,16,14, 4}, { 3, 1, 9,18,11}, {12,14,17,18,20}, { 7, 1, 3, 9, 5}} ind = diag[?,] sumDiag = 0   for x = 1 to diag[?,] for y = 1 to diag[,?]-ind sumDiag += diag[x, y] next y ind -= 1 next x   print "Sum of elements below main diagonal of matrix is "; sumDiag end
http://rosettacode.org/wiki/Sum_of_elements_below_main_diagonal_of_matrix
Sum of elements below main diagonal of matrix
Task Find and display the sum of elements that are below the main diagonal of a matrix. The matrix should be a square matrix. ───   Matrix to be used:   ─── [[1,3,7,8,10], [2,4,16,14,4], [3,1,9,18,11], [12,14,17,18,20], [7,1,3,9,5]]
#BQN
BQN
SumBelowDiagonal ← +´∘⥊⊢×(>⌜´)∘(↕¨≢)   matrix ← >⟨⟨ 1, 3, 7, 8,10⟩, ⟨ 2, 4,16,14, 4⟩, ⟨ 3, 1, 9,18,11⟩, ⟨12,14,17,18,20⟩, ⟨ 7, 1, 3, 9, 5⟩⟩   SumBelowDiagonal matrix
http://rosettacode.org/wiki/Sum_and_product_puzzle
Sum and product puzzle
Task[edit] Solve the "Impossible Puzzle": X and Y are two different whole numbers greater than 1. Their sum is no greater than 100, and Y is greater than X. S and P are two mathematicians (and consequently perfect logicians); S knows the sum X+Y and P knows the product X*Y. Both S and P know all the information in this paragraph. The following conversation occurs: S says "P does not know X and Y." P says "Now I know X and Y." S says "Now I also know X and Y!" What are X and Y? Guidance It can be hard to wrap one's head around what the three lines of dialog between S (the "sum guy") and P (the "product guy") convey about the values of X and Y. So for your convenience, here's a break-down: Quote Implied fact 1) S says "P does not know X and Y." For every possible sum decomposition of the number X+Y, the product has in turn more than one product decomposition. 2) P says "Now I know X and Y." The number X*Y has only one product decomposition for which fact 1 is true. 3) S says "Now I also know X and Y." The number X+Y has only one sum decomposition for which fact 2 is true. Terminology: "sum decomposition" of a number = Any pair of positive integers (A, B) so that A+B equals the number. Here, with the additional constraint 2 ≤ A < B. "product decomposition" of a number = Any pair of positive integers (A, B) so that A*B equals the number. Here, with the additional constraint 2 ≤ A < B. Your program can solve the puzzle by considering all possible pairs (X, Y) in the range 2 ≤ X < Y ≤ 98, and then successively eliminating candidates based on the three facts. It turns out only one solution remains! See the Python example for an implementation that uses this approach with a few optimizations. See also   Wikipedia:   Sum and Product Puzzle
#11l
11l
F counter(arr) DefaultDict[Int, Int] d L(a) arr d[a]++ R d   F decompose_sum(s) R (2 .< Int(s / 2 + 1)).map(a -> (a, @s - a))   Set[(Int, Int)] all_pairs_set L(a) 2..99 L(b) a + 1 .< 100 I a + b < 100 all_pairs_set.add((a, b)) V all_pairs = Array(all_pairs_set)   V product_counts = counter(all_pairs.map((c, d) -> c * d)) V unique_products = Set(all_pairs.filter((a, b) -> :product_counts[a * b] == 1)) V s_pairs = all_pairs.filter((a, b) -> all(decompose_sum(a + b).map((x, y) -> (x, y) !C :unique_products)))   product_counts = counter(s_pairs.map((c, d) -> c * d)) V p_pairs = s_pairs.filter((a, b) -> :product_counts[a * b] == 1)   V sum_counts = counter(p_pairs.map((c, d) -> c + d)) V final_pairs = p_pairs.filter((a, b) -> :sum_counts[a + b] == 1)   print(final_pairs)
http://rosettacode.org/wiki/Symmetric_difference
Symmetric difference
Task Given two sets A and B, compute ( A ∖ B ) ∪ ( B ∖ A ) . {\displaystyle (A\setminus B)\cup (B\setminus A).} That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B. In other words: ( A ∪ B ) ∖ ( A ∩ B ) {\displaystyle (A\cup B)\setminus (A\cap B)} (the set of items that are in at least one of A or B minus the set of items that are in both A and B). Optionally, give the individual differences ( A ∖ B {\displaystyle A\setminus B} and B ∖ A {\displaystyle B\setminus A} ) as well. Test cases A = {John, Bob, Mary, Serena} B = {Jim, Mary, John, Bob} Notes If your code uses lists of items to represent sets then ensure duplicate items in lists are correctly handled. For example two lists representing sets of a = ["John", "Serena", "Bob", "Mary", "Serena"] and b = ["Jim", "Mary", "John", "Jim", "Bob"] should produce the result of just two strings: ["Serena", "Jim"], in any order. In the mathematical notation above A \ B gives the set of items in A that are not in B; A ∪ B gives the set of items in both A and B, (their union); and A ∩ B gives the set of items that are in both A and B (their intersection).
#REBOL
REBOL
a: [John Serena Bob Mary Serena] b: [Jim Mary John Jim Bob] difference a b
http://rosettacode.org/wiki/Symmetric_difference
Symmetric difference
Task Given two sets A and B, compute ( A ∖ B ) ∪ ( B ∖ A ) . {\displaystyle (A\setminus B)\cup (B\setminus A).} That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B. In other words: ( A ∪ B ) ∖ ( A ∩ B ) {\displaystyle (A\cup B)\setminus (A\cap B)} (the set of items that are in at least one of A or B minus the set of items that are in both A and B). Optionally, give the individual differences ( A ∖ B {\displaystyle A\setminus B} and B ∖ A {\displaystyle B\setminus A} ) as well. Test cases A = {John, Bob, Mary, Serena} B = {Jim, Mary, John, Bob} Notes If your code uses lists of items to represent sets then ensure duplicate items in lists are correctly handled. For example two lists representing sets of a = ["John", "Serena", "Bob", "Mary", "Serena"] and b = ["Jim", "Mary", "John", "Jim", "Bob"] should produce the result of just two strings: ["Serena", "Jim"], in any order. In the mathematical notation above A \ B gives the set of items in A that are not in B; A ∪ B gives the set of items in both A and B, (their union); and A ∩ B gives the set of items that are in both A and B (their intersection).
#REXX
REXX
/*REXX program finds symmetric difference and symmetric AND (between two lists). */ a= '["John", "Serena", "Bob", "Mary", "Serena"]' /*note the duplicate element: Serena */ b= '["Jim", "Mary", "John", "Jim", "Bob"]' /* " " " " Jim */ a.=0; SD.=0; SA.=0; SD=; SA= /*falsify booleans; zero & nullify vars*/ a.1=a; say '──────────────list A =' a /*assign a list and display it to term.*/ a.2=b; say '──────────────list B =' b /* " " " " " " " " */ /* [↓] parse the two lists. */ do k=1 for 2 /*process both lists (stemmed array). */ a.k=strip( strip(a.k, , "["), ,']') /*strip leading and trailing brackets. */ do j=1 until a.k='' /*parse names [they may have blanks]. */ a.k=strip(a.k, , ',') /*strip all commas (if there are any). */ parse var a.k '"' _ '"' a.k /*obtain the name of the list. */ a.k.j=_ /*store the name of the list. */ a.k._=1 /*make a boolean value. */ end /*j*/ a.k.0=j-1 /*the number of this list (of names). */ end /*k*/ say /* [↓] find the symmetric difference. */ do k=1 for 2; ko=word(2 1, k) /*process both lists; KO=other list. */ do j=1 for a.k.0; _=a.k.j /*process the list names. */ if \a.ko._ & \SD._ then do; SD._=1 /*if not in both, then ··· */ SD=SD '"'_'",' /*add to symmetric difference list. */ end end /*j*/ end /*k*/ /* [↓] SD ≡ symmetric difference. */ SD= "["strip( strip(SD), 'T', ",")']' /*clean up and add brackets [ ] to it.*/ say 'symmetric difference =' SD /*display the symmetric difference. */ /* [↓] locate the symmetric AND. */ do j=1 for a.1.0; _=a.1.j /*process the A list names. */ if a.1._ & a.2._ & \SA._ then do; SA._=1 /*if it's common to both, then ··· */ SA=SA '"'_'",' /*add to symmetric AND list. */ end end /*j*/ say /* [↓] SA ≡ symmetric AND. */ SA= "["strip( strip(SA), 'T', ",")']' /*clean up and add brackets [ ] to it.*/ say ' symmetric AND =' SA /*stick a fork in it, we're all done. */
http://rosettacode.org/wiki/Temperature_conversion
Temperature conversion
There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones: Kelvin, Celsius, Fahrenheit, and Rankine. The Celsius and Kelvin scales have the same magnitude, but different null points. 0 degrees Celsius corresponds to 273.15 kelvin. 0 kelvin is absolute zero. The Fahrenheit and Rankine scales also have the same magnitude, but different null points. 0 degrees Fahrenheit corresponds to 459.67 degrees Rankine. 0 degrees Rankine is absolute zero. The Celsius/Kelvin and Fahrenheit/Rankine scales have a ratio of 5 : 9. Task Write code that accepts a value of kelvin, converts it to values of the three other scales, and prints the result. Example K 21.00 C -252.15 F -421.87 R 37.80
#Perl
Perl
my %scale = ( Celcius => { factor => 1 , offset => -273.15 }, Rankine => { factor => 1.8, offset => 0 }, Fahrenheit => { factor => 1.8, offset => -459.67 }, );   print "Enter a temperature in Kelvin: "; chomp(my $kelvin = <STDIN>); die "No such temperature!\n" unless $kelvin > 0;   foreach (sort keys %scale) { printf "%12s:%8.2f\n", $_, $kelvin * $scale{$_}{factor} + $scale{$_}{offset}; }
http://rosettacode.org/wiki/System_time
System time
Task Output the system time   (any units will do as long as they are noted) either by a system command or one built into the language. The system time can be used for debugging, network information, random number seeds, or something as simple as program performance. Related task   Date format See also   Retrieving system time (wiki)
#Objeck
Objeck
function : Time() ~ Nil { t := Time->New(); IO.Console->GetInstance()->Print(t->GetHours())->Print(":")->Print(t->GetMinutes())->Print(":")->PrintLine(t->GetSeconds()); }
http://rosettacode.org/wiki/System_time
System time
Task Output the system time   (any units will do as long as they are noted) either by a system command or one built into the language. The system time can be used for debugging, network information, random number seeds, or something as simple as program performance. Related task   Date format See also   Retrieving system time (wiki)
#Objective-C
Objective-C
NSLog(@"%@", [NSDate date]);
http://rosettacode.org/wiki/Sum_of_elements_below_main_diagonal_of_matrix
Sum of elements below main diagonal of matrix
Task Find and display the sum of elements that are below the main diagonal of a matrix. The matrix should be a square matrix. ───   Matrix to be used:   ─── [[1,3,7,8,10], [2,4,16,14,4], [3,1,9,18,11], [12,14,17,18,20], [7,1,3,9,5]]
#C
C
  #include<stdlib.h> #include<stdio.h>   typedef struct{ int rows,cols; int** dataSet; }matrix;   matrix readMatrix(char* dataFile){ FILE* fp = fopen(dataFile,"r"); matrix rosetta; int i,j;   fscanf(fp,"%d%d",&rosetta.rows,&rosetta.cols);   rosetta.dataSet = (int**)malloc(rosetta.rows*sizeof(int*));   for(i=0;i<rosetta.rows;i++){ rosetta.dataSet[i] = (int*)malloc(rosetta.cols*sizeof(int)); for(j=0;j<rosetta.cols;j++) fscanf(fp,"%d",&rosetta.dataSet[i][j]); }   fclose(fp); return rosetta; }   void printMatrix(matrix rosetta){ int i,j;   for(i=0;i<rosetta.rows;i++){ printf("\n"); for(j=0;j<rosetta.cols;j++) printf("%3d",rosetta.dataSet[i][j]); } }   int findSum(matrix rosetta){ int i,j,sum = 0;   for(i=1;i<rosetta.rows;i++){ for(j=0;j<i;j++){ sum += rosetta.dataSet[i][j]; } }   return sum; }   int main(int argC,char* argV[]) { if(argC!=2) return printf("Usage : %s <filename>",argV[0]);   matrix data = readMatrix(argV[1]);   printf("\n\nMatrix is : \n\n"); printMatrix(data);   printf("\n\nSum below main diagonal : %d",findSum(data));   return 0; }  
http://rosettacode.org/wiki/Sum_and_product_puzzle
Sum and product puzzle
Task[edit] Solve the "Impossible Puzzle": X and Y are two different whole numbers greater than 1. Their sum is no greater than 100, and Y is greater than X. S and P are two mathematicians (and consequently perfect logicians); S knows the sum X+Y and P knows the product X*Y. Both S and P know all the information in this paragraph. The following conversation occurs: S says "P does not know X and Y." P says "Now I know X and Y." S says "Now I also know X and Y!" What are X and Y? Guidance It can be hard to wrap one's head around what the three lines of dialog between S (the "sum guy") and P (the "product guy") convey about the values of X and Y. So for your convenience, here's a break-down: Quote Implied fact 1) S says "P does not know X and Y." For every possible sum decomposition of the number X+Y, the product has in turn more than one product decomposition. 2) P says "Now I know X and Y." The number X*Y has only one product decomposition for which fact 1 is true. 3) S says "Now I also know X and Y." The number X+Y has only one sum decomposition for which fact 2 is true. Terminology: "sum decomposition" of a number = Any pair of positive integers (A, B) so that A+B equals the number. Here, with the additional constraint 2 ≤ A < B. "product decomposition" of a number = Any pair of positive integers (A, B) so that A*B equals the number. Here, with the additional constraint 2 ≤ A < B. Your program can solve the puzzle by considering all possible pairs (X, Y) in the range 2 ≤ X < Y ≤ 98, and then successively eliminating candidates based on the three facts. It turns out only one solution remains! See the Python example for an implementation that uses this approach with a few optimizations. See also   Wikipedia:   Sum and Product Puzzle
#AWK
AWK
  # syntax: GAWK -f SUM_AND_PRODUCT_PUZZLE.AWK BEGIN { for (s=2; s<=100; s++) { if ((a=satisfies_statement3(s)) != 0) { printf("%d (%d+%d)\n",s,a,s-a) } } exit(0) } function satisfies_statement1(s, a) { # S says: P does not know the two numbers. # Given s, for all pairs (a,b), a+b=s, 2 <= a,b <= 99, true if at least one of a or b is composite for (a=2; a<=int(s/2); a++) { if (is_prime(a) && is_prime(s-a)) { return(0) } } return(1) } function satisfies_statement2(p, i,j,winner) { # P says: Now I know the two numbers. # Given p, for all pairs (a,b), a*b=p, 2 <= a,b <= 99, true if exactly one pair satisfies statement 1 for (i=2; i<=int(sqrt(p)); i++) { if (p % i == 0) { j = int(p/i) if (!(2 <= j && j <= 99)) { # in range continue } if (satisfies_statement1(i+j)) { if (winner) { return(0) } winner = 1 } } } return(winner) } function satisfies_statement3(s, a,b,winner) { # S says: Now I know the two numbers. # Given s, for all pairs (a,b), a+b=s, 2 <= a,b <= 99, true if exactly one pair satisfies statements 1 and 2 if (!satisfies_statement1(s)) { return(0) } for (a=2; a<=int(s/2); a++) { b = s - a if (satisfies_statement2(a*b)) { if (winner) { return(0) } winner = a } } return(winner) } function is_prime(x, i) { if (x <= 1) { return(0) } for (i=2; i<=int(sqrt(x)); i++) { if (x % i == 0) { return(0) } } return(1) }  
http://rosettacode.org/wiki/Symmetric_difference
Symmetric difference
Task Given two sets A and B, compute ( A ∖ B ) ∪ ( B ∖ A ) . {\displaystyle (A\setminus B)\cup (B\setminus A).} That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B. In other words: ( A ∪ B ) ∖ ( A ∩ B ) {\displaystyle (A\cup B)\setminus (A\cap B)} (the set of items that are in at least one of A or B minus the set of items that are in both A and B). Optionally, give the individual differences ( A ∖ B {\displaystyle A\setminus B} and B ∖ A {\displaystyle B\setminus A} ) as well. Test cases A = {John, Bob, Mary, Serena} B = {Jim, Mary, John, Bob} Notes If your code uses lists of items to represent sets then ensure duplicate items in lists are correctly handled. For example two lists representing sets of a = ["John", "Serena", "Bob", "Mary", "Serena"] and b = ["Jim", "Mary", "John", "Jim", "Bob"] should produce the result of just two strings: ["Serena", "Jim"], in any order. In the mathematical notation above A \ B gives the set of items in A that are not in B; A ∪ B gives the set of items in both A and B, (their union); and A ∩ B gives the set of items that are in both A and B (their intersection).
#Ring
Ring
  alist = [] blist = [] alist = ["john", "bob", "mary", "serena"] blist = ["jim", "mary", "john", "bob"]   alist2 = [] for i = 1 to len(alist) flag = 0 for j = 1 to len(blist) if alist[i] = blist[j] flag = 1 ok next if (flag = 0) add(alist2, alist[i]) ok next   blist2 = [] for j = 1 to len(alist) flag = 0 for i = 1 to len(blist) if alist[i] = blist[j] flag = 1 ok next if (flag = 0) add(blist2, blist[j]) ok next see "a xor b :" see nl see alist2 see blist2 see nl see "a-b :" see nl see alist2 see nl see "b-a :" see nl see blist2 see nl  
http://rosettacode.org/wiki/Symmetric_difference
Symmetric difference
Task Given two sets A and B, compute ( A ∖ B ) ∪ ( B ∖ A ) . {\displaystyle (A\setminus B)\cup (B\setminus A).} That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B. In other words: ( A ∪ B ) ∖ ( A ∩ B ) {\displaystyle (A\cup B)\setminus (A\cap B)} (the set of items that are in at least one of A or B minus the set of items that are in both A and B). Optionally, give the individual differences ( A ∖ B {\displaystyle A\setminus B} and B ∖ A {\displaystyle B\setminus A} ) as well. Test cases A = {John, Bob, Mary, Serena} B = {Jim, Mary, John, Bob} Notes If your code uses lists of items to represent sets then ensure duplicate items in lists are correctly handled. For example two lists representing sets of a = ["John", "Serena", "Bob", "Mary", "Serena"] and b = ["Jim", "Mary", "John", "Jim", "Bob"] should produce the result of just two strings: ["Serena", "Jim"], in any order. In the mathematical notation above A \ B gives the set of items in A that are not in B; A ∪ B gives the set of items in both A and B, (their union); and A ∩ B gives the set of items that are in both A and B (their intersection).
#Ruby
Ruby
a = ["John", "Serena", "Bob", "Mary", "Serena"] b = ["Jim", "Mary", "John", "Jim", "Bob"] # the union minus the intersection: p sym_diff = (a | b)-(a & b) # => ["Serena", "Jim"]
http://rosettacode.org/wiki/Temperature_conversion
Temperature conversion
There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones: Kelvin, Celsius, Fahrenheit, and Rankine. The Celsius and Kelvin scales have the same magnitude, but different null points. 0 degrees Celsius corresponds to 273.15 kelvin. 0 kelvin is absolute zero. The Fahrenheit and Rankine scales also have the same magnitude, but different null points. 0 degrees Fahrenheit corresponds to 459.67 degrees Rankine. 0 degrees Rankine is absolute zero. The Celsius/Kelvin and Fahrenheit/Rankine scales have a ratio of 5 : 9. Task Write code that accepts a value of kelvin, converts it to values of the three other scales, and prints the result. Example K 21.00 C -252.15 F -421.87 R 37.80
#Phix
Phix
atom K = prompt_number("Enter temperature in Kelvin >=0: ",{0,1e307}) printf(1," Kelvin: %5.2f\n Celsius: %5.2f\nFahrenheit: %5.2f\n Rankine: %5.2f\n\n", {K, K-273.15, K*1.8-459.67, K*1.8})
http://rosettacode.org/wiki/System_time
System time
Task Output the system time   (any units will do as long as they are noted) either by a system command or one built into the language. The system time can be used for debugging, network information, random number seeds, or something as simple as program performance. Related task   Date format See also   Retrieving system time (wiki)
#OCaml
OCaml
#load "unix.cma";; open Unix;; let {tm_sec = sec; tm_min = min; tm_hour = hour; tm_mday = mday; tm_mon = mon; tm_year = year; tm_wday = wday; tm_yday = yday; tm_isdst = isdst} = localtime (time ());; Printf.printf "%04d-%02d-%02d %02d:%02d:%02d\n" (year + 1900) (mon + 1) mday hour min sec;
http://rosettacode.org/wiki/Sum_of_elements_below_main_diagonal_of_matrix
Sum of elements below main diagonal of matrix
Task Find and display the sum of elements that are below the main diagonal of a matrix. The matrix should be a square matrix. ───   Matrix to be used:   ─── [[1,3,7,8,10], [2,4,16,14,4], [3,1,9,18,11], [12,14,17,18,20], [7,1,3,9,5]]
#C.2B.2B
C++
#include <iostream> #include <vector>   template<typename T> T sum_below_diagonal(const std::vector<std::vector<T>>& matrix) { T sum = 0; for (std::size_t y = 0; y < matrix.size(); y++) for (std::size_t x = 0; x < matrix[y].size() && x < y; x++) sum += matrix[y][x]; return sum; }   int main() { std::vector<std::vector<int>> matrix = { {1,3,7,8,10}, {2,4,16,14,4}, {3,1,9,18,11}, {12,14,17,18,20}, {7,1,3,9,5} };   std::cout << sum_below_diagonal(matrix) << std::endl; return 0; }
http://rosettacode.org/wiki/Sum_and_product_puzzle
Sum and product puzzle
Task[edit] Solve the "Impossible Puzzle": X and Y are two different whole numbers greater than 1. Their sum is no greater than 100, and Y is greater than X. S and P are two mathematicians (and consequently perfect logicians); S knows the sum X+Y and P knows the product X*Y. Both S and P know all the information in this paragraph. The following conversation occurs: S says "P does not know X and Y." P says "Now I know X and Y." S says "Now I also know X and Y!" What are X and Y? Guidance It can be hard to wrap one's head around what the three lines of dialog between S (the "sum guy") and P (the "product guy") convey about the values of X and Y. So for your convenience, here's a break-down: Quote Implied fact 1) S says "P does not know X and Y." For every possible sum decomposition of the number X+Y, the product has in turn more than one product decomposition. 2) P says "Now I know X and Y." The number X*Y has only one product decomposition for which fact 1 is true. 3) S says "Now I also know X and Y." The number X+Y has only one sum decomposition for which fact 2 is true. Terminology: "sum decomposition" of a number = Any pair of positive integers (A, B) so that A+B equals the number. Here, with the additional constraint 2 ≤ A < B. "product decomposition" of a number = Any pair of positive integers (A, B) so that A*B equals the number. Here, with the additional constraint 2 ≤ A < B. Your program can solve the puzzle by considering all possible pairs (X, Y) in the range 2 ≤ X < Y ≤ 98, and then successively eliminating candidates based on the three facts. It turns out only one solution remains! See the Python example for an implementation that uses this approach with a few optimizations. See also   Wikipedia:   Sum and Product Puzzle
#C
C
#include <stdbool.h> #include <stdio.h> #include <stdlib.h>   typedef struct node_t { int x, y; struct node_t *prev, *next; } node;   node *new_node(int x, int y) { node *n = malloc(sizeof(node)); n->x = x; n->y = y; n->next = NULL; n->prev = NULL; return n; }   void free_node(node **n) { if (n == NULL) { return; }   (*n)->prev = NULL; (*n)->next = NULL;   free(*n);   *n = NULL; }   typedef struct list_t { node *head; node *tail; } list;   list make_list() { list lst = { NULL, NULL }; return lst; }   void append_node(list *const lst, int x, int y) { if (lst == NULL) { return; }   node *n = new_node(x, y);   if (lst->head == NULL) { lst->head = n; lst->tail = n; } else { n->prev = lst->tail; lst->tail->next = n; lst->tail = n; } }   void remove_node(list *const lst, const node *const n) { if (lst == NULL || n == NULL) { return; }   if (n->prev != NULL) { n->prev->next = n->next; if (n->next != NULL) { n->next->prev = n->prev; } else { lst->tail = n->prev; } } else { if (n->next != NULL) { n->next->prev = NULL; lst->head = n->next; } }   free_node(&n); }   void free_list(list *const lst) { node *ptr;   if (lst == NULL) { return; } ptr = lst->head;   while (ptr != NULL) { node *nxt = ptr->next; free_node(&ptr); ptr = nxt; }   lst->head = NULL; lst->tail = NULL; }   void print_list(const list *lst) { node *it;   if (lst == NULL) { return; }   for (it = lst->head; it != NULL; it = it->next) { int sum = it->x + it->y; int prod = it->x * it->y; printf("[%d, %d] S=%d P=%d\n", it->x, it->y, sum, prod); } }   void print_count(const list *const lst) { node *it; int c = 0;   if (lst == NULL) { return; }   for (it = lst->head; it != NULL; it = it->next) { c++; }   if (c == 0) { printf("no candidates\n"); } else if (c == 1) { printf("one candidate\n"); } else { printf("%d candidates\n", c); } }   void setup(list *const lst) { int x, y;   if (lst == NULL) { return; }   // numbers must be greater than 1 for (x = 2; x <= 98; x++) { // numbers must be unique, and sum no more than 100 for (y = x + 1; y <= 98; y++) { if (x + y <= 100) { append_node(lst, x, y); } } } }   void remove_by_sum(list *const lst, const int sum) { node *it;   if (lst == NULL) { return; }   it = lst->head; while (it != NULL) { int s = it->x + it->y;   if (s == sum) { remove_node(lst, it); it = lst->head; } else { it = it->next; } } }   void remove_by_prod(list *const lst, const int prod) { node *it;   if (lst == NULL) { return; }   it = lst->head; while (it != NULL) { int p = it->x * it->y;   if (p == prod) { remove_node(lst, it); it = lst->head; } else { it = it->next; } } }   void statement1(list *const lst) { short *unique = calloc(100000, sizeof(short)); node *it, *nxt;   for (it = lst->head; it != NULL; it = it->next) { int prod = it->x * it->y; unique[prod]++; }   it = lst->head; while (it != NULL) { int prod = it->x * it->y; nxt = it->next; if (unique[prod] == 1) { remove_by_sum(lst, it->x + it->y); it = lst->head; } else { it = nxt; } }   free(unique); }   void statement2(list *const candidates) { short *unique = calloc(100000, sizeof(short)); node *it, *nxt;   for (it = candidates->head; it != NULL; it = it->next) { int prod = it->x * it->y; unique[prod]++; }   it = candidates->head; while (it != NULL) { int prod = it->x * it->y; nxt = it->next; if (unique[prod] > 1) { remove_by_prod(candidates, prod); it = candidates->head; } else { it = nxt; } }   free(unique); }   void statement3(list *const candidates) { short *unique = calloc(100, sizeof(short)); node *it, *nxt;   for (it = candidates->head; it != NULL; it = it->next) { int sum = it->x + it->y; unique[sum]++; }   it = candidates->head; while (it != NULL) { int sum = it->x + it->y; nxt = it->next; if (unique[sum] > 1) { remove_by_sum(candidates, sum); it = candidates->head; } else { it = nxt; } }   free(unique); }   int main() { list candidates = make_list();   setup(&candidates); print_count(&candidates);   statement1(&candidates); print_count(&candidates);   statement2(&candidates); print_count(&candidates);   statement3(&candidates); print_count(&candidates);   print_list(&candidates);   free_list(&candidates); return 0; }
http://rosettacode.org/wiki/Symmetric_difference
Symmetric difference
Task Given two sets A and B, compute ( A ∖ B ) ∪ ( B ∖ A ) . {\displaystyle (A\setminus B)\cup (B\setminus A).} That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B. In other words: ( A ∪ B ) ∖ ( A ∩ B ) {\displaystyle (A\cup B)\setminus (A\cap B)} (the set of items that are in at least one of A or B minus the set of items that are in both A and B). Optionally, give the individual differences ( A ∖ B {\displaystyle A\setminus B} and B ∖ A {\displaystyle B\setminus A} ) as well. Test cases A = {John, Bob, Mary, Serena} B = {Jim, Mary, John, Bob} Notes If your code uses lists of items to represent sets then ensure duplicate items in lists are correctly handled. For example two lists representing sets of a = ["John", "Serena", "Bob", "Mary", "Serena"] and b = ["Jim", "Mary", "John", "Jim", "Bob"] should produce the result of just two strings: ["Serena", "Jim"], in any order. In the mathematical notation above A \ B gives the set of items in A that are not in B; A ∪ B gives the set of items in both A and B, (their union); and A ∩ B gives the set of items that are in both A and B (their intersection).
#Run_BASIC
Run BASIC
  setA$ = "John,Bob,Mary,Serena" setB$ = "Jim,Mary,John,Bob"   x$ = b$(setA$,setB$) print word$(x$,1,",") c$ = c$ + x$   x$ = b$(setB$,setA$) print word$(x$,1,",") print c$;x$ end function b$(a$,b$) i = 1 while word$(a$,i,",") <> "" a1$ = word$(a$,i,",") j = instr(b$,a1$) if j <> 0 then b$ = left$(b$,j-1) + mid$(b$,j+len(a1$)+1) i = i + 1 wend end function
http://rosettacode.org/wiki/Symmetric_difference
Symmetric difference
Task Given two sets A and B, compute ( A ∖ B ) ∪ ( B ∖ A ) . {\displaystyle (A\setminus B)\cup (B\setminus A).} That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B. In other words: ( A ∪ B ) ∖ ( A ∩ B ) {\displaystyle (A\cup B)\setminus (A\cap B)} (the set of items that are in at least one of A or B minus the set of items that are in both A and B). Optionally, give the individual differences ( A ∖ B {\displaystyle A\setminus B} and B ∖ A {\displaystyle B\setminus A} ) as well. Test cases A = {John, Bob, Mary, Serena} B = {Jim, Mary, John, Bob} Notes If your code uses lists of items to represent sets then ensure duplicate items in lists are correctly handled. For example two lists representing sets of a = ["John", "Serena", "Bob", "Mary", "Serena"] and b = ["Jim", "Mary", "John", "Jim", "Bob"] should produce the result of just two strings: ["Serena", "Jim"], in any order. In the mathematical notation above A \ B gives the set of items in A that are not in B; A ∪ B gives the set of items in both A and B, (their union); and A ∩ B gives the set of items that are in both A and B (their intersection).
#Rust
Rust
use std::collections::HashSet;   fn main() { let a: HashSet<_> = ["John", "Bob", "Mary", "Serena"] .iter() .collect(); let b = ["Jim", "Mary", "John", "Bob"] .iter() .collect();   let diff = a.symmetric_difference(&b); println!("{:?}", diff); }  
http://rosettacode.org/wiki/Temperature_conversion
Temperature conversion
There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones: Kelvin, Celsius, Fahrenheit, and Rankine. The Celsius and Kelvin scales have the same magnitude, but different null points. 0 degrees Celsius corresponds to 273.15 kelvin. 0 kelvin is absolute zero. The Fahrenheit and Rankine scales also have the same magnitude, but different null points. 0 degrees Fahrenheit corresponds to 459.67 degrees Rankine. 0 degrees Rankine is absolute zero. The Celsius/Kelvin and Fahrenheit/Rankine scales have a ratio of 5 : 9. Task Write code that accepts a value of kelvin, converts it to values of the three other scales, and prints the result. Example K 21.00 C -252.15 F -421.87 R 37.80
#PHP
PHP
    while (true) { echo "\nEnter a value in kelvin (q to quit): "; if ($kelvin = trim(fgets(STDIN))) { if ($kelvin == 'q') { echo 'quitting'; break; } if (is_numeric($kelvin)) { $kelvin = floatVal($kelvin); if ($kelvin >= 0) { printf(" K %2.2f\n", $kelvin); printf(" C %2.2f\n", $kelvin - 273.15); printf(" F %2.2f\n", $kelvin * 1.8 - 459.67); printf(" R %2.2f\n", $kelvin * 1.8); } else printf(" %2.2f K is below absolute zero\n", $kelvin); } } }
http://rosettacode.org/wiki/System_time
System time
Task Output the system time   (any units will do as long as they are noted) either by a system command or one built into the language. The system time can be used for debugging, network information, random number seeds, or something as simple as program performance. Related task   Date format See also   Retrieving system time (wiki)
#Oforth
Oforth
System.tick println #[ #sqrt 1000000 seq map sum println ] bench
http://rosettacode.org/wiki/System_time
System time
Task Output the system time   (any units will do as long as they are noted) either by a system command or one built into the language. The system time can be used for debugging, network information, random number seeds, or something as simple as program performance. Related task   Date format See also   Retrieving system time (wiki)
#Oz
Oz
{Show {OS.time}} %% posix time (seconds since 1970-01-01) {Show {OS.gmTime}} %% current UTC as a record {Show {OS.localTime}} %% current local time as record   %% Also interesting: undocumented module OsTime %% When did posix time reach 1 billion? {Show {OsTime.gmtime 1000000000}} {Show {OsTime.localtime 1000000000}}
http://rosettacode.org/wiki/Sum_of_elements_below_main_diagonal_of_matrix
Sum of elements below main diagonal of matrix
Task Find and display the sum of elements that are below the main diagonal of a matrix. The matrix should be a square matrix. ───   Matrix to be used:   ─── [[1,3,7,8,10], [2,4,16,14,4], [3,1,9,18,11], [12,14,17,18,20], [7,1,3,9,5]]
#Excel
Excel
=LAMBDA(isUpper, LAMBDA(matrix, LET( nCols, COLUMNS(matrix), nRows, ROWS(matrix), ixs, SEQUENCE(nRows, nCols, 0, 1), x, MOD(ixs, nCols), y, QUOTIENT(ixs, nRows),   IF(nCols=nRows, LET( p, LAMBDA(x, y, IF(isUpper, x > y, x < y) ),   IF(p(x, y), INDEX(matrix, 1 + y, 1 + x), 0 ) ), "Matrix not square" ) ) ) )
http://rosettacode.org/wiki/Sum_of_elements_below_main_diagonal_of_matrix
Sum of elements below main diagonal of matrix
Task Find and display the sum of elements that are below the main diagonal of a matrix. The matrix should be a square matrix. ───   Matrix to be used:   ─── [[1,3,7,8,10], [2,4,16,14,4], [3,1,9,18,11], [12,14,17,18,20], [7,1,3,9,5]]
#F.23
F#
  // Sum below leading diagnal. Nigel Galloway: July 21st., 2021 let _,n=[[ 1; 3; 7; 8;10]; [ 2; 4;16;14; 4]; [ 3; 1; 9;18;11]; [12;14;17;18;20]; [ 7; 1; 3; 9; 5]]|>List.fold(fun(n,g) i->let i,_=i|>List.splitAt n in (n+1,g+(i|>List.sum)))(0,0) in printfn "%d" n  
http://rosettacode.org/wiki/Sum_and_product_puzzle
Sum and product puzzle
Task[edit] Solve the "Impossible Puzzle": X and Y are two different whole numbers greater than 1. Their sum is no greater than 100, and Y is greater than X. S and P are two mathematicians (and consequently perfect logicians); S knows the sum X+Y and P knows the product X*Y. Both S and P know all the information in this paragraph. The following conversation occurs: S says "P does not know X and Y." P says "Now I know X and Y." S says "Now I also know X and Y!" What are X and Y? Guidance It can be hard to wrap one's head around what the three lines of dialog between S (the "sum guy") and P (the "product guy") convey about the values of X and Y. So for your convenience, here's a break-down: Quote Implied fact 1) S says "P does not know X and Y." For every possible sum decomposition of the number X+Y, the product has in turn more than one product decomposition. 2) P says "Now I know X and Y." The number X*Y has only one product decomposition for which fact 1 is true. 3) S says "Now I also know X and Y." The number X+Y has only one sum decomposition for which fact 2 is true. Terminology: "sum decomposition" of a number = Any pair of positive integers (A, B) so that A+B equals the number. Here, with the additional constraint 2 ≤ A < B. "product decomposition" of a number = Any pair of positive integers (A, B) so that A*B equals the number. Here, with the additional constraint 2 ≤ A < B. Your program can solve the puzzle by considering all possible pairs (X, Y) in the range 2 ≤ X < Y ≤ 98, and then successively eliminating candidates based on the three facts. It turns out only one solution remains! See the Python example for an implementation that uses this approach with a few optimizations. See also   Wikipedia:   Sum and Product Puzzle
#C.2B.2B
C++
#include <algorithm> #include <iostream> #include <map> #include <vector>   std::ostream &operator<<(std::ostream &os, std::vector<std::pair<int, int>> &v) { for (auto &p : v) { auto sum = p.first + p.second; auto prod = p.first * p.second; os << '[' << p.first << ", " << p.second << "] S=" << sum << " P=" << prod; } return os << '\n'; }   void print_count(const std::vector<std::pair<int, int>> &candidates) { auto c = candidates.size(); if (c == 0) { std::cout << "no candidates\n"; } else if (c == 1) { std::cout << "one candidate\n"; } else { std::cout << c << " candidates\n"; } }   auto setup() { std::vector<std::pair<int, int>> candidates;   // numbers must be greater than 1 for (int x = 2; x <= 98; x++) { // numbers must be unique, and sum no more than 100 for (int y = x + 1; y <= 98; y++) { if (x + y <= 100) { candidates.push_back(std::make_pair(x, y)); } } }   return candidates; }   void remove_by_sum(std::vector<std::pair<int, int>> &candidates, const int sum) { candidates.erase(std::remove_if( candidates.begin(), candidates.end(), [sum](const std::pair<int, int> &pair) { auto s = pair.first + pair.second; return s == sum; } ), candidates.end()); }   void remove_by_prod(std::vector<std::pair<int, int>> &candidates, const int prod) { candidates.erase(std::remove_if( candidates.begin(), candidates.end(), [prod](const std::pair<int, int> &pair) { auto p = pair.first * pair.second; return p == prod; } ), candidates.end()); }   void statement1(std::vector<std::pair<int, int>> &candidates) { std::map<int, int> uniqueMap;   std::for_each( candidates.cbegin(), candidates.cend(), [&uniqueMap](const std::pair<int, int> &pair) { auto prod = pair.first * pair.second; uniqueMap[prod]++; } );   bool loop; do { loop = false; for (auto &pair : candidates) { auto prod = pair.first * pair.second; if (uniqueMap[prod] == 1) { auto sum = pair.first + pair.second; remove_by_sum(candidates, sum);   loop = true; break; } } } while (loop); }   void statement2(std::vector<std::pair<int, int>> &candidates) { std::map<int, int> uniqueMap;   std::for_each( candidates.cbegin(), candidates.cend(), [&uniqueMap](const std::pair<int, int> &pair) { auto prod = pair.first * pair.second; uniqueMap[prod]++; } );   bool loop; do { loop = false; for (auto &pair : candidates) { auto prod = pair.first * pair.second; if (uniqueMap[prod] > 1) { remove_by_prod(candidates, prod);   loop = true; break; } } } while (loop); }   void statement3(std::vector<std::pair<int, int>> &candidates) { std::map<int, int> uniqueMap;   std::for_each( candidates.cbegin(), candidates.cend(), [&uniqueMap](const std::pair<int, int> &pair) { auto sum = pair.first + pair.second; uniqueMap[sum]++; } );   bool loop; do { loop = false; for (auto &pair : candidates) { auto sum = pair.first + pair.second; if (uniqueMap[sum] > 1) { remove_by_sum(candidates, sum);   loop = true; break; } } } while (loop); }   int main() { auto candidates = setup(); print_count(candidates);   statement1(candidates); print_count(candidates);   statement2(candidates); print_count(candidates);   statement3(candidates); print_count(candidates);   std::cout << candidates;   return 0; }
http://rosettacode.org/wiki/Symmetric_difference
Symmetric difference
Task Given two sets A and B, compute ( A ∖ B ) ∪ ( B ∖ A ) . {\displaystyle (A\setminus B)\cup (B\setminus A).} That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B. In other words: ( A ∪ B ) ∖ ( A ∩ B ) {\displaystyle (A\cup B)\setminus (A\cap B)} (the set of items that are in at least one of A or B minus the set of items that are in both A and B). Optionally, give the individual differences ( A ∖ B {\displaystyle A\setminus B} and B ∖ A {\displaystyle B\setminus A} ) as well. Test cases A = {John, Bob, Mary, Serena} B = {Jim, Mary, John, Bob} Notes If your code uses lists of items to represent sets then ensure duplicate items in lists are correctly handled. For example two lists representing sets of a = ["John", "Serena", "Bob", "Mary", "Serena"] and b = ["Jim", "Mary", "John", "Jim", "Bob"] should produce the result of just two strings: ["Serena", "Jim"], in any order. In the mathematical notation above A \ B gives the set of items in A that are not in B; A ∪ B gives the set of items in both A and B, (their union); and A ∩ B gives the set of items that are in both A and B (their intersection).
#Scala
Scala
scala> val s1 = Set("John", "Serena", "Bob", "Mary", "Serena") s1: scala.collection.immutable.Set[java.lang.String] = Set(John, Serena, Bob, Mary)   scala> val s2 = Set("Jim", "Mary", "John", "Jim", "Bob") s2: scala.collection.immutable.Set[java.lang.String] = Set(Jim, Mary, John, Bob)   scala> (s1 diff s2) union (s2 diff s1) res46: scala.collection.immutable.Set[java.lang.String] = Set(Serena, Jim)
http://rosettacode.org/wiki/Temperature_conversion
Temperature conversion
There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones: Kelvin, Celsius, Fahrenheit, and Rankine. The Celsius and Kelvin scales have the same magnitude, but different null points. 0 degrees Celsius corresponds to 273.15 kelvin. 0 kelvin is absolute zero. The Fahrenheit and Rankine scales also have the same magnitude, but different null points. 0 degrees Fahrenheit corresponds to 459.67 degrees Rankine. 0 degrees Rankine is absolute zero. The Celsius/Kelvin and Fahrenheit/Rankine scales have a ratio of 5 : 9. Task Write code that accepts a value of kelvin, converts it to values of the three other scales, and prints the result. Example K 21.00 C -252.15 F -421.87 R 37.80
#PicoLisp
PicoLisp
(scl 2)   (de convertKelvin (Kelvin) (for X (quote (K . prog) (C (K) (- K 273.15)) (F (K) (- (*/ K 1.8 1.0) 459.67)) (R (K) (*/ K 1.8 1.0)) ) (tab (-3 8) (car X) (format ((cdr X) Kelvin) *Scl) ) ) )
http://rosettacode.org/wiki/Temperature_conversion
Temperature conversion
There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones: Kelvin, Celsius, Fahrenheit, and Rankine. The Celsius and Kelvin scales have the same magnitude, but different null points. 0 degrees Celsius corresponds to 273.15 kelvin. 0 kelvin is absolute zero. The Fahrenheit and Rankine scales also have the same magnitude, but different null points. 0 degrees Fahrenheit corresponds to 459.67 degrees Rankine. 0 degrees Rankine is absolute zero. The Celsius/Kelvin and Fahrenheit/Rankine scales have a ratio of 5 : 9. Task Write code that accepts a value of kelvin, converts it to values of the three other scales, and prints the result. Example K 21.00 C -252.15 F -421.87 R 37.80
#PL.2FI
PL/I
*process source attributes xref; /* PL/I ************************************************************** * 15.08.2013 Walter Pachl translated from NetRexx * temperatures below 0K are considered invalid *********************************************************************/ temperature: Proc Options(main); Dcl sysin record Input; On Endfile(sysin) Goto eoj; On Record(sysin); Dcl 1 dat, 2 t Pic'SSSS9V.99', 2 * char( 1), 2 from char(10), 2 * char( 1), 2 to char(10); Do Forever; Read File(sysin) Into(dat); If tc(t,from,'KELVIN')<0 Then Put Edit('Input (',t,from,') invalid. Below absolute zero') (Skip,a,f(8,2),x(1),a,a); Else Put edit(t,from,' -> ',tc(t,from,to),to) (skip,f(8,2),x(1),a(10),a,f(8,2),x(1),a(10)); End; eoj: Return;   tc: Procedure(T,scaleFrom,scaleTo) Returns(Dec Fixed(8,2)); Dcl t Pic'SSSS9V.99'; Dcl (val) Dec Fixed(8,2); Dcl (scaleFrom,scaleTo) Char(10); select(scaleFrom); when('KELVIN ') do; select(scaleTo); when('KELVIN ') val = T; when('CELSIUS ') val = T - 273.15; when('FAHRENHEIT') val = T * 9 / 5 - 459.67; when('RANKINE ') val = T * 9 / 5; when('DELISLE ') val = (373.15 - T) * 3 / 2; when('NEWTON ') val = (T - 273.15) * 33 / 100; when('REAUMUR ') val = (T - 273.15) * 4 / 5; when('ROEMER ') val = (T - 273.15) * 21 / 40 + 7.5; otherwise Do; Put Edit('scaleTo=',scaleTo)(Skip,a,a); Call err(1); End; end; end; when('CELSIUS') do; select(scaleTo); when('KELVIN ') val = T + 273.15; when('CELSIUS ') val = T; when('FAHRENHEIT') val = T * 9 / 5 + 32; when('RANKINE ') val = (T + 273.15) * 9 / 5; when('DELISLE ') val = (100 - T) * 3 / 2; when('NEWTON ') val = T * 33 / 100; when('REAUMUR ') val = T * 4 / 5; when('ROEMER ') val = T * 21 / 40 + 7.5; otherwise Call err(2); end; end; when('FAHRENHEIT') do; select(scaleTo); when('KELVIN ') val = (T + 459.67) * 5 / 9; when('CELSIUS ') val = (T - 32) * 5 / 9; when('FAHRENHEIT') val = T; when('RANKINE ') val = T + 459.67; when('DELISLE ') val = (212 - T) * 5 / 6; when('NEWTON ') val = (T - 32) * 11 / 60; when('REAUMUR ') val = (T - 32) * 4 / 9; when('ROEMER ') val = (T - 32) * 7 / 24 + 7.5; otherwise Call err(3); end; end; when('RANKINE') do; select(scaleTo); when('KELVIN ') val = T * 5 / 9; when('CELSIUS ') val = (T - 491.67) * 5 / 9; when('FAHRENHEIT') val = T - 459.67; when('RANKINE ') val = T; when('DELISLE ') val = (671.67 - T) * 5 / 6; when('NEWTON ') val = (T - 491.67) * 11 / 60; when('REAUMUR ') val = (T - 491.67) * 4 / 9; when('ROEMER ') val = (T - 491.67) * 7 / 24 + 7.5; otherwise Call err(4); end; end; when('DELISLE') do; select(scaleTo); when('KELVIN ') val = 373.15 - T * 2 / 3; when('CELSIUS ') val = 100 - T * 2 / 3; when('FAHRENHEIT') val = 212 - T * 6 / 5; when('RANKINE ') val = 671.67 - T * 6 / 5; when('DELISLE ') val = T; when('NEWTON ') val = 33 - T * 11 / 50; when('REAUMUR ') val = 80 - T * 8 / 15; when('ROEMER ') val = 60 - T * 7 / 20; otherwise Call err(5); end; end; when('NEWTON') do; select(scaleTo); when('KELVIN ') val = T * 100 / 33 + 273.15; when('CELSIUS ') val = T * 100 / 33; when('FAHRENHEIT') val = T * 60 / 11 + 32; when('RANKINE ') val = T * 60 / 11 + 491.67; when('DELISLE ') val = (33 - T) * 50 / 11; when('NEWTON ') val = T; when('REAUMUR ') val = T * 80 / 33; when('ROEMER ') val = T * 35 / 22 + 7.5; otherwise Call err(6); end; end; when('REAUMUR') do; select(scaleTo); when('KELVIN ') val = T * 5 / 4 + 273.15; when('CELSIUS ') val = T * 5 / 4; when('FAHRENHEIT') val = T * 9 / 4 + 32; when('RANKINE ') val = T * 9 / 4 + 491.67; when('DELISLE ') val = (80 - T) * 15 / 8; when('NEWTON ') val = T * 33 / 80; when('REAUMUR ') val = T; when('ROEMER ') val = T * 21 / 32 + 7.5; otherwise Call err(7); end; end; when('ROEMER') do; select(scaleTo); when('KELVIN ') val = (T - 7.5) * 40 / 21 + 273.15; when('CELSIUS ') val = (T - 7.5) * 40 / 21; when('FAHRENHEIT') val = (T - 7.5) * 24 / 7 + 32; when('RANKINE ') val = (T - 7.5) * 24 / 7 + 491.67; when('DELISLE ') val = (60 - T) * 20 / 7; when('NEWTON ') val = (T - 7.5) * 22 / 35; when('REAUMUR ') val = (T - 7.5) * 32 / 21; when('ROEMER ') val = T; otherwise Call err(8); end; end; otherwise Call err(9); end; return(val); err: Proc(e); Dcl e Dec fixed(1); Put Edit('error ',e,' invalid input')(Skip,a,f(1),a); val=0; End; End; End;
http://rosettacode.org/wiki/System_time
System time
Task Output the system time   (any units will do as long as they are noted) either by a system command or one built into the language. The system time can be used for debugging, network information, random number seeds, or something as simple as program performance. Related task   Date format See also   Retrieving system time (wiki)
#PARI.2FGP
PARI/GP
system("date")
http://rosettacode.org/wiki/System_time
System time
Task Output the system time   (any units will do as long as they are noted) either by a system command or one built into the language. The system time can be used for debugging, network information, random number seeds, or something as simple as program performance. Related task   Date format See also   Retrieving system time (wiki)
#Pascal
Pascal
type timeStamp = packed record dateValid: Boolean; year: integer; month: 1..12; day: 1..31; timeValid: Boolean; hour: 0..23; minute: 0..59; second: 0..59; end;
http://rosettacode.org/wiki/Sum_of_elements_below_main_diagonal_of_matrix
Sum of elements below main diagonal of matrix
Task Find and display the sum of elements that are below the main diagonal of a matrix. The matrix should be a square matrix. ───   Matrix to be used:   ─── [[1,3,7,8,10], [2,4,16,14,4], [3,1,9,18,11], [12,14,17,18,20], [7,1,3,9,5]]
#Factor
Factor
USING: kernel math math.matrices prettyprint sequences ;   : sum-below-diagonal ( matrix -- sum ) dup square-matrix? [ "Matrix must be square." throw ] unless 0 swap [ head sum + ] each-index ;   { { 1 3 7 8 10 } { 2 4 16 14 4 } { 3 1 9 18 11 } { 12 14 17 18 20 } { 7 1 3 9 5 } } sum-below-diagonal .
http://rosettacode.org/wiki/Sum_of_elements_below_main_diagonal_of_matrix
Sum of elements below main diagonal of matrix
Task Find and display the sum of elements that are below the main diagonal of a matrix. The matrix should be a square matrix. ───   Matrix to be used:   ─── [[1,3,7,8,10], [2,4,16,14,4], [3,1,9,18,11], [12,14,17,18,20], [7,1,3,9,5]]
#Go
Go
package main   import ( "fmt" "log" )   func main() { m := [][]int{ {1, 3, 7, 8, 10}, {2, 4, 16, 14, 4}, {3, 1, 9, 18, 11}, {12, 14, 17, 18, 20}, {7, 1, 3, 9, 5}, } if len(m) != len(m[0]) { log.Fatal("Matrix must be square.") } sum := 0 for i := 1; i < len(m); i++ { for j := 0; j < i; j++ { sum = sum + m[i][j] } } fmt.Println("Sum of elements below main diagonal is", sum) }
http://rosettacode.org/wiki/Sum_and_product_puzzle
Sum and product puzzle
Task[edit] Solve the "Impossible Puzzle": X and Y are two different whole numbers greater than 1. Their sum is no greater than 100, and Y is greater than X. S and P are two mathematicians (and consequently perfect logicians); S knows the sum X+Y and P knows the product X*Y. Both S and P know all the information in this paragraph. The following conversation occurs: S says "P does not know X and Y." P says "Now I know X and Y." S says "Now I also know X and Y!" What are X and Y? Guidance It can be hard to wrap one's head around what the three lines of dialog between S (the "sum guy") and P (the "product guy") convey about the values of X and Y. So for your convenience, here's a break-down: Quote Implied fact 1) S says "P does not know X and Y." For every possible sum decomposition of the number X+Y, the product has in turn more than one product decomposition. 2) P says "Now I know X and Y." The number X*Y has only one product decomposition for which fact 1 is true. 3) S says "Now I also know X and Y." The number X+Y has only one sum decomposition for which fact 2 is true. Terminology: "sum decomposition" of a number = Any pair of positive integers (A, B) so that A+B equals the number. Here, with the additional constraint 2 ≤ A < B. "product decomposition" of a number = Any pair of positive integers (A, B) so that A*B equals the number. Here, with the additional constraint 2 ≤ A < B. Your program can solve the puzzle by considering all possible pairs (X, Y) in the range 2 ≤ X < Y ≤ 98, and then successively eliminating candidates based on the three facts. It turns out only one solution remains! See the Python example for an implementation that uses this approach with a few optimizations. See also   Wikipedia:   Sum and Product Puzzle
#C.23
C#
using System; using System.Linq; using System.Collections.Generic;   public class Program { public static void Main() { const int maxSum = 100; var pairs = ( from X in 2.To(maxSum / 2 - 1) from Y in (X + 1).To(maxSum - 2).TakeWhile(y => X + y <= maxSum) select new { X, Y, S = X + Y, P = X * Y } ).ToHashSet();   Console.WriteLine(pairs.Count);   var uniqueP = pairs.GroupBy(pair => pair.P).Where(g => g.Count() == 1).Select(g => g.Key).ToHashSet();   pairs.ExceptWith(pairs.GroupBy(pair => pair.S).Where(g => g.Any(pair => uniqueP.Contains(pair.P))).SelectMany(g => g)); Console.WriteLine(pairs.Count);   pairs.ExceptWith(pairs.GroupBy(pair => pair.P).Where(g => g.Count() > 1).SelectMany(g => g)); Console.WriteLine(pairs.Count);   pairs.ExceptWith(pairs.GroupBy(pair => pair.S).Where(g => g.Count() > 1).SelectMany(g => g)); Console.WriteLine(pairs.Count);   foreach (var pair in pairs) Console.WriteLine(pair); } }   public static class Extensions { public static IEnumerable<int> To(this int start, int end) { for (int i = start; i <= end; i++) yield return i; }   public static HashSet<T> ToHashSet<T>(this IEnumerable<T> source) => new HashSet<T>(source); }
http://rosettacode.org/wiki/Symmetric_difference
Symmetric difference
Task Given two sets A and B, compute ( A ∖ B ) ∪ ( B ∖ A ) . {\displaystyle (A\setminus B)\cup (B\setminus A).} That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B. In other words: ( A ∪ B ) ∖ ( A ∩ B ) {\displaystyle (A\cup B)\setminus (A\cap B)} (the set of items that are in at least one of A or B minus the set of items that are in both A and B). Optionally, give the individual differences ( A ∖ B {\displaystyle A\setminus B} and B ∖ A {\displaystyle B\setminus A} ) as well. Test cases A = {John, Bob, Mary, Serena} B = {Jim, Mary, John, Bob} Notes If your code uses lists of items to represent sets then ensure duplicate items in lists are correctly handled. For example two lists representing sets of a = ["John", "Serena", "Bob", "Mary", "Serena"] and b = ["Jim", "Mary", "John", "Jim", "Bob"] should produce the result of just two strings: ["Serena", "Jim"], in any order. In the mathematical notation above A \ B gives the set of items in A that are not in B; A ∪ B gives the set of items in both A and B, (their union); and A ∩ B gives the set of items that are in both A and B (their intersection).
#Scheme
Scheme
  (import (scheme base) (scheme write))   ;; -- given two sets represented as lists, return (A \ B) (define (a-without-b a b) (cond ((null? a) '()) ((member (car a) (cdr a)) ; drop head of a if it's a duplicate (a-without-b (cdr a) b)) ((member (car a) b) ; head of a is in b so drop it (a-without-b (cdr a) b)) (else ; head of a not in b, so keep it (cons (car a) (a-without-b (cdr a) b)))))   ;; -- given two sets represented as lists, return symmetric difference (define (symmetric-difference a b) (append (a-without-b a b) (a-without-b b a)))   ;; -- test case (define A '(John Bob Mary Serena)) (define B '(Jim Mary John Bob))   (display "A\\B: ") (display (a-without-b A B)) (newline) (display "B\\A: ") (display (a-without-b B A)) (newline) (display "Symmetric difference: ") (display (symmetric-difference A B)) (newline) ;; -- extra test as we are using lists (display "Symmetric difference 2: ") (display (symmetric-difference '(John Serena Bob Mary Serena) '(Jim Mary John Jim Bob))) (newline)  
http://rosettacode.org/wiki/Temperature_conversion
Temperature conversion
There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones: Kelvin, Celsius, Fahrenheit, and Rankine. The Celsius and Kelvin scales have the same magnitude, but different null points. 0 degrees Celsius corresponds to 273.15 kelvin. 0 kelvin is absolute zero. The Fahrenheit and Rankine scales also have the same magnitude, but different null points. 0 degrees Fahrenheit corresponds to 459.67 degrees Rankine. 0 degrees Rankine is absolute zero. The Celsius/Kelvin and Fahrenheit/Rankine scales have a ratio of 5 : 9. Task Write code that accepts a value of kelvin, converts it to values of the three other scales, and prints the result. Example K 21.00 C -252.15 F -421.87 R 37.80
#Plain_English
Plain English
To run: Start up. Put 21 into a kelvin temperature. Show the kelvin temperature in various temperature scales. Wait for the escape key. Shut down.   A temperature is a fraction. A kelvin temperature is a temperature. A celsius temperature is a temperature. A rankine temperature is a temperature. A fahrenheit temperature is a temperature.   To convert a kelvin temperature to a celsius temperature: Put the kelvin temperature minus 273-15/100 into the celsius temperature.   To convert a kelvin temperature to a rankine temperature: Put the kelvin temperature times 9/5 into the rankine temperature.   To convert a kelvin temperature to a fahrenheit temperature: Convert the kelvin temperature to a rankine temperature. Put the rankine temperature minus 459-67/100 into the fahrenheit temperature.   To show a temperature given a temperature scale string: Write the temperature scale then " = " then the temperature then " degrees" on the console.   To show a kelvin temperature in various temperature scales: Convert the kelvin temperature to a celsius temperature. Convert the kelvin temperature to a fahrenheit temperature. Convert the kelvin temperature to a rankine temperature. Show the kelvin temperature given "K". Show the celsius temperature given "C". Show the fahrenheit temperature given "F". Show the rankine temperature given "R".
http://rosettacode.org/wiki/System_time
System time
Task Output the system time   (any units will do as long as they are noted) either by a system command or one built into the language. The system time can be used for debugging, network information, random number seeds, or something as simple as program performance. Related task   Date format See also   Retrieving system time (wiki)
#Perl
Perl
print scalar localtime, "\n";
http://rosettacode.org/wiki/System_time
System time
Task Output the system time   (any units will do as long as they are noted) either by a system command or one built into the language. The system time can be used for debugging, network information, random number seeds, or something as simple as program performance. Related task   Date format See also   Retrieving system time (wiki)
#Phix
Phix
include timedate.e ?format_timedate(date(),"Dddd, Mmmm dth, YYYY, h:mm:ss pm") atom t0 = time() sleep(0.9) ?time()-t0
http://rosettacode.org/wiki/Sum_of_elements_below_main_diagonal_of_matrix
Sum of elements below main diagonal of matrix
Task Find and display the sum of elements that are below the main diagonal of a matrix. The matrix should be a square matrix. ───   Matrix to be used:   ─── [[1,3,7,8,10], [2,4,16,14,4], [3,1,9,18,11], [12,14,17,18,20], [7,1,3,9,5]]
#Haskell
Haskell
----------------- UPPER OR LOWER TRIANGLE ----------------   matrixTriangle :: Bool -> [[a]] -> Either String [[a]] matrixTriangle upper matrix | upper = go drop id | otherwise = go take pred where go f g | isSquare matrix = (Right . snd) $ foldr (\xs (n, rows) -> (pred n, f n xs : rows)) (g $ length matrix, []) matrix | otherwise = Left "Defined only for a square matrix."   isSquare :: [[a]] -> Bool isSquare rows = all ((n ==) . length) rows where n = length rows   --------------------------- TEST ------------------------- main :: IO () main = mapM_ putStrLn $ zipWith ( flip ((<>) . (<> " triangle:\n\t")) . either id (show . sum . concat) ) ( [matrixTriangle] <*> [False, True] <*> [ [ [1, 3, 7, 8, 10], [2, 4, 16, 14, 4], [3, 1, 9, 18, 11], [12, 14, 17, 18, 20], [7, 1, 3, 9, 5] ] ] ) ["Lower", "Upper"]
http://rosettacode.org/wiki/Sum_and_product_puzzle
Sum and product puzzle
Task[edit] Solve the "Impossible Puzzle": X and Y are two different whole numbers greater than 1. Their sum is no greater than 100, and Y is greater than X. S and P are two mathematicians (and consequently perfect logicians); S knows the sum X+Y and P knows the product X*Y. Both S and P know all the information in this paragraph. The following conversation occurs: S says "P does not know X and Y." P says "Now I know X and Y." S says "Now I also know X and Y!" What are X and Y? Guidance It can be hard to wrap one's head around what the three lines of dialog between S (the "sum guy") and P (the "product guy") convey about the values of X and Y. So for your convenience, here's a break-down: Quote Implied fact 1) S says "P does not know X and Y." For every possible sum decomposition of the number X+Y, the product has in turn more than one product decomposition. 2) P says "Now I know X and Y." The number X*Y has only one product decomposition for which fact 1 is true. 3) S says "Now I also know X and Y." The number X+Y has only one sum decomposition for which fact 2 is true. Terminology: "sum decomposition" of a number = Any pair of positive integers (A, B) so that A+B equals the number. Here, with the additional constraint 2 ≤ A < B. "product decomposition" of a number = Any pair of positive integers (A, B) so that A*B equals the number. Here, with the additional constraint 2 ≤ A < B. Your program can solve the puzzle by considering all possible pairs (X, Y) in the range 2 ≤ X < Y ≤ 98, and then successively eliminating candidates based on the three facts. It turns out only one solution remains! See the Python example for an implementation that uses this approach with a few optimizations. See also   Wikipedia:   Sum and Product Puzzle
#Common_Lisp
Common Lisp
  ;;; Calculate all x's and their possible y's. (defparameter *x-possibleys* (loop for x from 2 to 49 collect (cons x (loop for y from (- 100 x) downto (1+ x) collect y))) "For every x there are certain y's, with respect to the rules of the puzzle")   (defun xys-operation (op x-possibleys) "returns an alist of ((x possible-y) . (op x possible-y))" (let ((x (car x-possibleys)) (ys (cdr x-possibleys))) (mapcar #'(lambda (y) (cons (list x y) (funcall op x y))) ys)))   (defun sp-numbers (op x-possibleys) "generates all possible sums or products of the puzzle" (loop for xys in x-possibleys append (xys-operation op xys)))   (defun group-sp (sp-numbers) "sp: Sum or Product" (loop for sp-number in (remove-duplicates sp-numbers :key #'cdr) collect (cons (cdr sp-number) (mapcar #'car (remove-if-not #'(lambda (sp) (= sp (cdr sp-number))) sp-numbers :key #'cdr)))))   (defun statement-1a (sum-groups) "remove all sums with a single possible xy" (remove-if #'(lambda (xys) (= (list-length xys) 1)) sum-groups :key #'cdr))   (defun statement-1b (x-possibleys) "S says: P does not know X and Y." (let ((multi-xy-sums (statement-1a (group-sp (sp-numbers #'+ x-possibleys)))) (products (group-sp (sp-numbers #'* x-possibleys)))) (flet ((sum-has-xy-which-leads-to-unique-prod (sum-xys) ;; is there any product with a single possible xy? (some #'(lambda (prod-xys) (= (list-length (cdr prod-xys)) 1)) ;; all possible xys of the sum's (* x ys) (mapcar #'(lambda (xy) (assoc (apply #'* xy) products)) (cdr sum-xys))))) ;; remove sums with even one xy which leads to a unique product (remove-if #'sum-has-xy-which-leads-to-unique-prod multi-xy-sums))))   (defun remaining-products (remaining-sums-xys) "P's number is one of these" (loop for sum-xys in remaining-sums-xys append (loop for xy in (cdr sum-xys) collect (apply #'* xy))))   (defun statement-2 (remaining-sums-xys) "P says: Now I know X and Y." (let ((remaining-products (remaining-products remaining-sums-xys))) (mapcar #'(lambda (a-sum-unit) (cons (car a-sum-unit) (mapcar #'(lambda (xy) (list (count (apply #'* xy) remaining-products) xy)) (cdr a-sum-unit)))) remaining-sums-xys)))   (defun statement-3 (remaining-sums-with-their-products-occurrences-info) "S says: Now I also know X and Y." (remove-if #'(lambda (sum-xys) ;; remove those sums which have more than 1 product, that ;; appear only once amongst all remaining products (> (count 1 sum-xys :key #'car) 1)) remaining-sums-with-their-products-occurrences-info :key #'cdr))   (defun solution (survivor-sum-and-its-xys) "Now we know X and Y too :-D" (let* ((sum (caar survivor-sum-and-its-xys)) (xys (cdar survivor-sum-and-its-xys)) (xy (second (find 1 xys :key #'car)))) (pairlis '(x y sum product) (list (first xy) (second xy) sum (apply #'* xy)))))     (solution (statement-3 (statement-2 (statement-1b *x-possibleys*)))) ;; => ((PRODUCT . 52) (SUM . 17) (Y . 13) (X . 4))  
http://rosettacode.org/wiki/Symmetric_difference
Symmetric difference
Task Given two sets A and B, compute ( A ∖ B ) ∪ ( B ∖ A ) . {\displaystyle (A\setminus B)\cup (B\setminus A).} That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B. In other words: ( A ∪ B ) ∖ ( A ∩ B ) {\displaystyle (A\cup B)\setminus (A\cap B)} (the set of items that are in at least one of A or B minus the set of items that are in both A and B). Optionally, give the individual differences ( A ∖ B {\displaystyle A\setminus B} and B ∖ A {\displaystyle B\setminus A} ) as well. Test cases A = {John, Bob, Mary, Serena} B = {Jim, Mary, John, Bob} Notes If your code uses lists of items to represent sets then ensure duplicate items in lists are correctly handled. For example two lists representing sets of a = ["John", "Serena", "Bob", "Mary", "Serena"] and b = ["Jim", "Mary", "John", "Jim", "Bob"] should produce the result of just two strings: ["Serena", "Jim"], in any order. In the mathematical notation above A \ B gives the set of items in A that are not in B; A ∪ B gives the set of items in both A and B, (their union); and A ∩ B gives the set of items that are in both A and B (their intersection).
#Seed7
Seed7
$ include "seed7_05.s7i";   const type: striSet is set of string;   enable_output(striSet);   const proc: main is func local const striSet: setA is {"John", "Bob" , "Mary", "Serena"}; const striSet: setB is {"Jim" , "Mary", "John", "Bob" }; begin writeln(setA >< setB); end func;
http://rosettacode.org/wiki/Symmetric_difference
Symmetric difference
Task Given two sets A and B, compute ( A ∖ B ) ∪ ( B ∖ A ) . {\displaystyle (A\setminus B)\cup (B\setminus A).} That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B. In other words: ( A ∪ B ) ∖ ( A ∩ B ) {\displaystyle (A\cup B)\setminus (A\cap B)} (the set of items that are in at least one of A or B minus the set of items that are in both A and B). Optionally, give the individual differences ( A ∖ B {\displaystyle A\setminus B} and B ∖ A {\displaystyle B\setminus A} ) as well. Test cases A = {John, Bob, Mary, Serena} B = {Jim, Mary, John, Bob} Notes If your code uses lists of items to represent sets then ensure duplicate items in lists are correctly handled. For example two lists representing sets of a = ["John", "Serena", "Bob", "Mary", "Serena"] and b = ["Jim", "Mary", "John", "Jim", "Bob"] should produce the result of just two strings: ["Serena", "Jim"], in any order. In the mathematical notation above A \ B gives the set of items in A that are not in B; A ∪ B gives the set of items in both A and B, (their union); and A ∩ B gives the set of items that are in both A and B (their intersection).
#Sidef
Sidef
var a = ["John", "Serena", "Bob", "Mary", "Serena"]; var b = ["Jim", "Mary", "John", "Jim", "Bob"]; a ^ b -> unique.dump.say;
http://rosettacode.org/wiki/Temperature_conversion
Temperature conversion
There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones: Kelvin, Celsius, Fahrenheit, and Rankine. The Celsius and Kelvin scales have the same magnitude, but different null points. 0 degrees Celsius corresponds to 273.15 kelvin. 0 kelvin is absolute zero. The Fahrenheit and Rankine scales also have the same magnitude, but different null points. 0 degrees Fahrenheit corresponds to 459.67 degrees Rankine. 0 degrees Rankine is absolute zero. The Celsius/Kelvin and Fahrenheit/Rankine scales have a ratio of 5 : 9. Task Write code that accepts a value of kelvin, converts it to values of the three other scales, and prints the result. Example K 21.00 C -252.15 F -421.87 R 37.80
#PowerShell
PowerShell
function temp($k){ try{ $c = $k - 273.15 $r = $k / 5 * 9 $f = $r - 459.67 } catch { Write-host "Input error." return }   Write-host "" Write-host " TEMP (Kelvin)  : " $k Write-host " TEMP (Celsius)  : " $c Write-host " TEMP (Fahrenheit): " $f Write-host " TEMP (Rankine)  : " $r Write-host ""   }   $input=Read-host "Enter a temperature in Kelvin" temp $input
http://rosettacode.org/wiki/System_time
System time
Task Output the system time   (any units will do as long as they are noted) either by a system command or one built into the language. The system time can be used for debugging, network information, random number seeds, or something as simple as program performance. Related task   Date format See also   Retrieving system time (wiki)
#Phixmonti
Phixmonti
def printList len for get print endfor enddef   time   "Actual time is " swap 1 get " hour, " rot 2 get " minutes, " rot 3 get nip " seconds, " "and elapsed " msec " seconds of running time." 10 tolist printList
http://rosettacode.org/wiki/System_time
System time
Task Output the system time   (any units will do as long as they are noted) either by a system command or one built into the language. The system time can be used for debugging, network information, random number seeds, or something as simple as program performance. Related task   Date format See also   Retrieving system time (wiki)
#PHP
PHP
echo time(), "\n";
http://rosettacode.org/wiki/Sum_of_elements_below_main_diagonal_of_matrix
Sum of elements below main diagonal of matrix
Task Find and display the sum of elements that are below the main diagonal of a matrix. The matrix should be a square matrix. ───   Matrix to be used:   ─── [[1,3,7,8,10], [2,4,16,14,4], [3,1,9,18,11], [12,14,17,18,20], [7,1,3,9,5]]
#J
J
sum_below_diagonal =: [:+/@,[*>/~@i.@#
http://rosettacode.org/wiki/Sum_of_elements_below_main_diagonal_of_matrix
Sum of elements below main diagonal of matrix
Task Find and display the sum of elements that are below the main diagonal of a matrix. The matrix should be a square matrix. ───   Matrix to be used:   ─── [[1,3,7,8,10], [2,4,16,14,4], [3,1,9,18,11], [12,14,17,18,20], [7,1,3,9,5]]
#JavaScript
JavaScript
(() => { "use strict";   // -------- LOWER TRIANGLE OF A SQUARE MATRIX --------   // lowerTriangle :: [[a]] -> Either String [[a]] const lowerTriangle = matrix => // Either a message, if the matrix is not square, // or the lower triangle of the matrix. isSquare(matrix) ? ( Right( matrix.reduce( ([n, rows], xs) => [ 1 + n, rows.concat([xs.slice(0, n)]) ], [0, []] )[1] ) ) : Left("Not a square matrix");     // isSquare :: [[a]] -> Bool const isSquare = rows => { // True if the length of every row in the matrix // matches the number of rows in the matrix. const n = rows.length;   return rows.every(x => n === x.length); };   // ---------------------- TEST ----------------------- const main = () => either( msg => `Lower triangle undefined :: ${msg}` )( rows => sum([].concat(...rows)) )( lowerTriangle([ [1, 3, 7, 8, 10], [2, 4, 16, 14, 4], [3, 1, 9, 18, 11], [12, 14, 17, 18, 20], [7, 1, 3, 9, 5] ]) );   // --------------------- GENERIC ---------------------   // Left :: a -> Either a b const Left = x => ({ type: "Either", Left: x });     // Right :: b -> Either a b const Right = x => ({ type: "Either", Right: x });     // either :: (a -> c) -> (b -> c) -> Either a b -> c const either = fl => // Application of the function fl to the // contents of any Left value in e, or // the application of fr to its Right value. fr => e => e.Left ? ( fl(e.Left) ) : fr(e.Right);     // sum :: [Num] -> Num const sum = xs => // The numeric sum of all values in xs. xs.reduce((a, x) => a + x, 0);   // MAIN --- return main(); })();
http://rosettacode.org/wiki/Sum_and_product_puzzle
Sum and product puzzle
Task[edit] Solve the "Impossible Puzzle": X and Y are two different whole numbers greater than 1. Their sum is no greater than 100, and Y is greater than X. S and P are two mathematicians (and consequently perfect logicians); S knows the sum X+Y and P knows the product X*Y. Both S and P know all the information in this paragraph. The following conversation occurs: S says "P does not know X and Y." P says "Now I know X and Y." S says "Now I also know X and Y!" What are X and Y? Guidance It can be hard to wrap one's head around what the three lines of dialog between S (the "sum guy") and P (the "product guy") convey about the values of X and Y. So for your convenience, here's a break-down: Quote Implied fact 1) S says "P does not know X and Y." For every possible sum decomposition of the number X+Y, the product has in turn more than one product decomposition. 2) P says "Now I know X and Y." The number X*Y has only one product decomposition for which fact 1 is true. 3) S says "Now I also know X and Y." The number X+Y has only one sum decomposition for which fact 2 is true. Terminology: "sum decomposition" of a number = Any pair of positive integers (A, B) so that A+B equals the number. Here, with the additional constraint 2 ≤ A < B. "product decomposition" of a number = Any pair of positive integers (A, B) so that A*B equals the number. Here, with the additional constraint 2 ≤ A < B. Your program can solve the puzzle by considering all possible pairs (X, Y) in the range 2 ≤ X < Y ≤ 98, and then successively eliminating candidates based on the three facts. It turns out only one solution remains! See the Python example for an implementation that uses this approach with a few optimizations. See also   Wikipedia:   Sum and Product Puzzle
#D
D
void main() { import std.stdio, std.algorithm, std.range, std.typecons;   const s1 = cartesianProduct(iota(1, 101), iota(1, 101)) .filter!(p => 1 < p[0] && p[0] < p[1] && p[0] + p[1] < 100) .array;   alias P = const Tuple!(int, int); enum add = (P p) => p[0] + p[1]; enum mul = (P p) => p[0] * p[1]; enum sumEq = (P p) => s1.filter!(q => add(q) == add(p)); enum mulEq = (P p) => s1.filter!(q => mul(q) == mul(p));   const s2 = s1.filter!(p => sumEq(p).all!(q => mulEq(q).walkLength != 1)).array; const s3 = s2.filter!(p => mulEq(p).setIntersection(s2).walkLength == 1).array; s3.filter!(p => sumEq(p).setIntersection(s3).walkLength == 1).writeln; }
http://rosettacode.org/wiki/Symmetric_difference
Symmetric difference
Task Given two sets A and B, compute ( A ∖ B ) ∪ ( B ∖ A ) . {\displaystyle (A\setminus B)\cup (B\setminus A).} That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B. In other words: ( A ∪ B ) ∖ ( A ∩ B ) {\displaystyle (A\cup B)\setminus (A\cap B)} (the set of items that are in at least one of A or B minus the set of items that are in both A and B). Optionally, give the individual differences ( A ∖ B {\displaystyle A\setminus B} and B ∖ A {\displaystyle B\setminus A} ) as well. Test cases A = {John, Bob, Mary, Serena} B = {Jim, Mary, John, Bob} Notes If your code uses lists of items to represent sets then ensure duplicate items in lists are correctly handled. For example two lists representing sets of a = ["John", "Serena", "Bob", "Mary", "Serena"] and b = ["Jim", "Mary", "John", "Jim", "Bob"] should produce the result of just two strings: ["Serena", "Jim"], in any order. In the mathematical notation above A \ B gives the set of items in A that are not in B; A ∪ B gives the set of items in both A and B, (their union); and A ∩ B gives the set of items that are in both A and B (their intersection).
#Smalltalk
Smalltalk
|A B| A := Set new. B := Set new. A addAll: #( 'John' 'Bob' 'Mary' 'Serena' ). B addAll: #( 'Jim' 'Mary' 'John' 'Bob' ).   ( (A - B) + (B - A) ) displayNl.
http://rosettacode.org/wiki/Symmetric_difference
Symmetric difference
Task Given two sets A and B, compute ( A ∖ B ) ∪ ( B ∖ A ) . {\displaystyle (A\setminus B)\cup (B\setminus A).} That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B. In other words: ( A ∪ B ) ∖ ( A ∩ B ) {\displaystyle (A\cup B)\setminus (A\cap B)} (the set of items that are in at least one of A or B minus the set of items that are in both A and B). Optionally, give the individual differences ( A ∖ B {\displaystyle A\setminus B} and B ∖ A {\displaystyle B\setminus A} ) as well. Test cases A = {John, Bob, Mary, Serena} B = {Jim, Mary, John, Bob} Notes If your code uses lists of items to represent sets then ensure duplicate items in lists are correctly handled. For example two lists representing sets of a = ["John", "Serena", "Bob", "Mary", "Serena"] and b = ["Jim", "Mary", "John", "Jim", "Bob"] should produce the result of just two strings: ["Serena", "Jim"], in any order. In the mathematical notation above A \ B gives the set of items in A that are not in B; A ∪ B gives the set of items in both A and B, (their union); and A ∩ B gives the set of items that are in both A and B (their intersection).
#SQL.2FPostgreSQL
SQL/PostgreSQL
CREATE OR REPLACE FUNCTION arrxor(anyarray,anyarray) RETURNS anyarray AS $$ SELECT ARRAY( ( SELECT r.elements FROM ( (SELECT 1,unnest($1)) UNION ALL (SELECT 2,unnest($2)) ) AS r (arr, elements) GROUP BY 1 HAVING MIN(arr) = MAX(arr) ) ) $$ LANGUAGE SQL strict immutable;
http://rosettacode.org/wiki/Temperature_conversion
Temperature conversion
There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones: Kelvin, Celsius, Fahrenheit, and Rankine. The Celsius and Kelvin scales have the same magnitude, but different null points. 0 degrees Celsius corresponds to 273.15 kelvin. 0 kelvin is absolute zero. The Fahrenheit and Rankine scales also have the same magnitude, but different null points. 0 degrees Fahrenheit corresponds to 459.67 degrees Rankine. 0 degrees Rankine is absolute zero. The Celsius/Kelvin and Fahrenheit/Rankine scales have a ratio of 5 : 9. Task Write code that accepts a value of kelvin, converts it to values of the three other scales, and prints the result. Example K 21.00 C -252.15 F -421.87 R 37.80
#Pure_Data
Pure Data
#N canvas 200 200 640 600 10; #X floatatom 130 54 8 0 0 2 Kelvin chgk -; #X obj 130 453 rnd2; #X floatatom 130 493 8 0 0 1 K - -; #X floatatom 251 54 8 0 0 2 Celsius chgc -; #X obj 251 453 rnd2; #X floatatom 251 493 8 0 0 1 °C - -; #X floatatom 374 54 8 0 0 2 Fahrenheit chgf -; #X obj 374 453 rnd2; #X floatatom 374 493 8 0 0 1 °F - -; #X floatatom 498 54 8 0 0 2 Rankine chgr -; #X obj 498 453 rnd2; #X floatatom 498 493 8 0 0 1 °Ra - -; #X obj 65 133 - 273.15; #X obj 65 244 * 1.8; #X obj 65 267 + 32; #X obj 65 363 + 459.67; #X obj 186 133 * 1.8; #X obj 186 156 + 32; #X obj 186 268 + 459.67; #X obj 186 310 / 1.8; #X obj 309 133 + 459.67; #X obj 309 215 / 1.8; #X obj 309 291 - 273.15; #X obj 433 133 / 1.8; #X obj 433 223 - 273.15; #X obj 433 294 * 1.8; #X obj 433 317 + 32; #X text 20 53 Input:; #X text 20 492 Output:; #X connect 0 0 1 0; #X connect 0 0 12 0; #X connect 1 0 2 0; #X connect 3 0 4 0; #X connect 3 0 16 0; #X connect 4 0 5 0; #X connect 6 0 7 0; #X connect 6 0 20 0; #X connect 7 0 8 0; #X connect 9 0 10 0; #X connect 9 0 23 0; #X connect 10 0 11 0; #X connect 12 0 13 0; #X connect 12 0 4 0; #X connect 13 0 14 0; #X connect 14 0 15 0; #X connect 14 0 7 0; #X connect 15 0 10 0; #X connect 16 0 17 0; #X connect 17 0 18 0; #X connect 17 0 7 0; #X connect 18 0 19 0; #X connect 18 0 10 0; #X connect 19 0 1 0; #X connect 20 0 21 0; #X connect 20 0 10 0; #X connect 21 0 22 0; #X connect 21 0 1 0; #X connect 22 0 4 0; #X connect 23 0 24 0; #X connect 23 0 1 0; #X connect 24 0 25 0; #X connect 24 0 4 0; #X connect 25 0 26 0; #X connect 26 0 7 0;
http://rosettacode.org/wiki/Temperature_conversion
Temperature conversion
There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones: Kelvin, Celsius, Fahrenheit, and Rankine. The Celsius and Kelvin scales have the same magnitude, but different null points. 0 degrees Celsius corresponds to 273.15 kelvin. 0 kelvin is absolute zero. The Fahrenheit and Rankine scales also have the same magnitude, but different null points. 0 degrees Fahrenheit corresponds to 459.67 degrees Rankine. 0 degrees Rankine is absolute zero. The Celsius/Kelvin and Fahrenheit/Rankine scales have a ratio of 5 : 9. Task Write code that accepts a value of kelvin, converts it to values of the three other scales, and prints the result. Example K 21.00 C -252.15 F -421.87 R 37.80
#PureBasic
PureBasic
Procedure.d Kelvin2Celsius(tK.d)  : ProcedureReturn tK-273.15  : EndProcedure Procedure.d Kelvin2Fahrenheit(tK.d) : ProcedureReturn tK*1.8-459.67 : EndProcedure Procedure.d Kelvin2Rankine(tK.d)  : ProcedureReturn tK*1.8  : EndProcedure   OpenConsole() Repeat Print("Temperatur Kelvin? ") : Kelvin.d = ValD(Input()) PrintN("Conversion:") PrintN(#TAB$+"Celsius "+#TAB$+RSet(StrD(Kelvin2Celsius(Kelvin),2),8,Chr(32))) PrintN(#TAB$+"Fahrenheit"+#TAB$+RSet(StrD(Kelvin2Fahrenheit(Kelvin),2),8,Chr(32))) PrintN(#TAB$+"Rankine "+#TAB$+RSet(StrD(Kelvin2Rankine(Kelvin),2),8,Chr(32))) PrintN("ESC = End.") Repeat k$=Inkey() : Delay(50) : If RawKey()=#ESC : End : EndIf Until RawKey() ForEver
http://rosettacode.org/wiki/System_time
System time
Task Output the system time   (any units will do as long as they are noted) either by a system command or one built into the language. The system time can be used for debugging, network information, random number seeds, or something as simple as program performance. Related task   Date format See also   Retrieving system time (wiki)
#PicoLisp
PicoLisp
(stamp)
http://rosettacode.org/wiki/System_time
System time
Task Output the system time   (any units will do as long as they are noted) either by a system command or one built into the language. The system time can be used for debugging, network information, random number seeds, or something as simple as program performance. Related task   Date format See also   Retrieving system time (wiki)
#Pike
Pike
write( ctime(time()) );
http://rosettacode.org/wiki/Sum_of_elements_below_main_diagonal_of_matrix
Sum of elements below main diagonal of matrix
Task Find and display the sum of elements that are below the main diagonal of a matrix. The matrix should be a square matrix. ───   Matrix to be used:   ─── [[1,3,7,8,10], [2,4,16,14,4], [3,1,9,18,11], [12,14,17,18,20], [7,1,3,9,5]]
#jq
jq
  def add(s): reduce s as $x (null; . + $x);   # input: a square matrix def sum_below_diagonal: add( range(0;length) as $i | .[$i][:$i][] ) ;  
http://rosettacode.org/wiki/Sum_of_elements_below_main_diagonal_of_matrix
Sum of elements below main diagonal of matrix
Task Find and display the sum of elements that are below the main diagonal of a matrix. The matrix should be a square matrix. ───   Matrix to be used:   ─── [[1,3,7,8,10], [2,4,16,14,4], [3,1,9,18,11], [12,14,17,18,20], [7,1,3,9,5]]
#Julia
Julia
using LinearAlgebra   A = [ 1 3 7 8 10; 2 4 16 14 4; 3 1 9 18 11; 12 14 17 18 20; 7 1 3 9 5 ]   @show tril(A)   @show tril(A, -1)   @show sum(tril(A, -1)) # 69  
http://rosettacode.org/wiki/Sum_and_product_puzzle
Sum and product puzzle
Task[edit] Solve the "Impossible Puzzle": X and Y are two different whole numbers greater than 1. Their sum is no greater than 100, and Y is greater than X. S and P are two mathematicians (and consequently perfect logicians); S knows the sum X+Y and P knows the product X*Y. Both S and P know all the information in this paragraph. The following conversation occurs: S says "P does not know X and Y." P says "Now I know X and Y." S says "Now I also know X and Y!" What are X and Y? Guidance It can be hard to wrap one's head around what the three lines of dialog between S (the "sum guy") and P (the "product guy") convey about the values of X and Y. So for your convenience, here's a break-down: Quote Implied fact 1) S says "P does not know X and Y." For every possible sum decomposition of the number X+Y, the product has in turn more than one product decomposition. 2) P says "Now I know X and Y." The number X*Y has only one product decomposition for which fact 1 is true. 3) S says "Now I also know X and Y." The number X+Y has only one sum decomposition for which fact 2 is true. Terminology: "sum decomposition" of a number = Any pair of positive integers (A, B) so that A+B equals the number. Here, with the additional constraint 2 ≤ A < B. "product decomposition" of a number = Any pair of positive integers (A, B) so that A*B equals the number. Here, with the additional constraint 2 ≤ A < B. Your program can solve the puzzle by considering all possible pairs (X, Y) in the range 2 ≤ X < Y ≤ 98, and then successively eliminating candidates based on the three facts. It turns out only one solution remains! See the Python example for an implementation that uses this approach with a few optimizations. See also   Wikipedia:   Sum and Product Puzzle
#Elixir
Elixir
defmodule Puzzle do def sum_and_product do s1 = for x <- 2..49, y <- x+1..99, x+y<100, do: {x,y} s2 = Enum.filter(s1, fn p -> Enum.all?(sumEq(s1,p), fn q -> length(mulEq(s1,q)) != 1 end) end) s3 = Enum.filter(s2, fn p -> only1?(mulEq(s1,p), s2) end) Enum.filter(s3, fn p -> only1?(sumEq(s1,p), s3) end) |> IO.inspect end   defp add({x,y}), do: x + y   defp mul({x,y}), do: x * y   defp sumEq(s, p), do: Enum.filter(s, fn q -> add(p) == add(q) end)   defp mulEq(s, p), do: Enum.filter(s, fn q -> mul(p) == mul(q) end)   defp only1?(a, b) do MapSet.size(MapSet.intersection(MapSet.new(a), MapSet.new(b))) == 1 end end   Puzzle.sum_and_product
http://rosettacode.org/wiki/Symmetric_difference
Symmetric difference
Task Given two sets A and B, compute ( A ∖ B ) ∪ ( B ∖ A ) . {\displaystyle (A\setminus B)\cup (B\setminus A).} That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B. In other words: ( A ∪ B ) ∖ ( A ∩ B ) {\displaystyle (A\cup B)\setminus (A\cap B)} (the set of items that are in at least one of A or B minus the set of items that are in both A and B). Optionally, give the individual differences ( A ∖ B {\displaystyle A\setminus B} and B ∖ A {\displaystyle B\setminus A} ) as well. Test cases A = {John, Bob, Mary, Serena} B = {Jim, Mary, John, Bob} Notes If your code uses lists of items to represent sets then ensure duplicate items in lists are correctly handled. For example two lists representing sets of a = ["John", "Serena", "Bob", "Mary", "Serena"] and b = ["Jim", "Mary", "John", "Jim", "Bob"] should produce the result of just two strings: ["Serena", "Jim"], in any order. In the mathematical notation above A \ B gives the set of items in A that are not in B; A ∪ B gives the set of items in both A and B, (their union); and A ∩ B gives the set of items that are in both A and B (their intersection).
#Swift
Swift
let setA : Set<String> = ["John", "Bob", "Mary", "Serena"] let setB : Set<String> = ["Jim", "Mary", "John", "Bob"] println(setA.exclusiveOr(setB)) // symmetric difference of A and B println(setA.subtract(setB)) // elements in A that are not in B
http://rosettacode.org/wiki/Symmetric_difference
Symmetric difference
Task Given two sets A and B, compute ( A ∖ B ) ∪ ( B ∖ A ) . {\displaystyle (A\setminus B)\cup (B\setminus A).} That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B. In other words: ( A ∪ B ) ∖ ( A ∩ B ) {\displaystyle (A\cup B)\setminus (A\cap B)} (the set of items that are in at least one of A or B minus the set of items that are in both A and B). Optionally, give the individual differences ( A ∖ B {\displaystyle A\setminus B} and B ∖ A {\displaystyle B\setminus A} ) as well. Test cases A = {John, Bob, Mary, Serena} B = {Jim, Mary, John, Bob} Notes If your code uses lists of items to represent sets then ensure duplicate items in lists are correctly handled. For example two lists representing sets of a = ["John", "Serena", "Bob", "Mary", "Serena"] and b = ["Jim", "Mary", "John", "Jim", "Bob"] should produce the result of just two strings: ["Serena", "Jim"], in any order. In the mathematical notation above A \ B gives the set of items in A that are not in B; A ∪ B gives the set of items in both A and B, (their union); and A ∩ B gives the set of items that are in both A and B (their intersection).
#Tcl
Tcl
package require struct::set   set A {John Bob Mary Serena} set B {Jim Mary John Bob}   set AnotB [struct::set difference $A $B] set BnotA [struct::set difference $B $A] set SymDiff [struct::set union $AnotB $BnotA]   puts "A\\B = $AnotB" puts "B\\A = $BnotA" puts "A\u2296B = $SymDiff"   # Of course, the library already has this operation directly... puts "Direct Check: [struct::set symdiff $A $B]"
http://rosettacode.org/wiki/Temperature_conversion
Temperature conversion
There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones: Kelvin, Celsius, Fahrenheit, and Rankine. The Celsius and Kelvin scales have the same magnitude, but different null points. 0 degrees Celsius corresponds to 273.15 kelvin. 0 kelvin is absolute zero. The Fahrenheit and Rankine scales also have the same magnitude, but different null points. 0 degrees Fahrenheit corresponds to 459.67 degrees Rankine. 0 degrees Rankine is absolute zero. The Celsius/Kelvin and Fahrenheit/Rankine scales have a ratio of 5 : 9. Task Write code that accepts a value of kelvin, converts it to values of the three other scales, and prints the result. Example K 21.00 C -252.15 F -421.87 R 37.80
#Python
Python
>>> while True: k = float(input('K ? ')) print("%g Kelvin = %g Celsius = %g Fahrenheit = %g Rankine degrees."  % (k, k - 273.15, k * 1.8 - 459.67, k * 1.8))     K ? 21.0 21 Kelvin = -252.15 Celsius = -421.87 Fahrenheit = 37.8 Rankine degrees. K ? 222.2 222.2 Kelvin = -50.95 Celsius = -59.71 Fahrenheit = 399.96 Rankine degrees. K ?
http://rosettacode.org/wiki/System_time
System time
Task Output the system time   (any units will do as long as they are noted) either by a system command or one built into the language. The system time can be used for debugging, network information, random number seeds, or something as simple as program performance. Related task   Date format See also   Retrieving system time (wiki)
#PL.2FI
PL/I
put (datetime()); /* writes out the date and time */ /* The time is given to thousandths of a second, */ /* in the format hhmiss999 */ put (time()); /* gives the time in the format hhmiss999. */
http://rosettacode.org/wiki/System_time
System time
Task Output the system time   (any units will do as long as they are noted) either by a system command or one built into the language. The system time can be used for debugging, network information, random number seeds, or something as simple as program performance. Related task   Date format See also   Retrieving system time (wiki)
#PowerShell
PowerShell
Get-Date
http://rosettacode.org/wiki/Sum_of_elements_below_main_diagonal_of_matrix
Sum of elements below main diagonal of matrix
Task Find and display the sum of elements that are below the main diagonal of a matrix. The matrix should be a square matrix. ───   Matrix to be used:   ─── [[1,3,7,8,10], [2,4,16,14,4], [3,1,9,18,11], [12,14,17,18,20], [7,1,3,9,5]]
#Mathematica.2FWolfram_Language
Mathematica/Wolfram Language
m = {{1, 3, 7, 8, 10}, {2, 4, 16, 14, 4}, {3, 1, 9, 18, 11}, {12, 14, 17, 18, 20}, {7, 1, 3, 9, 5}}; Total[LowerTriangularize[m, -1], 2]
http://rosettacode.org/wiki/Sum_of_elements_below_main_diagonal_of_matrix
Sum of elements below main diagonal of matrix
Task Find and display the sum of elements that are below the main diagonal of a matrix. The matrix should be a square matrix. ───   Matrix to be used:   ─── [[1,3,7,8,10], [2,4,16,14,4], [3,1,9,18,11], [12,14,17,18,20], [7,1,3,9,5]]
#MiniZinc
MiniZinc
  % Sum below leading diagnal. Nigel Galloway: July 22nd., 2021 array [1..5,1..5] of int: N=[|1,3,7,8,10|2,4,16,14,4|3,1,9,18,11|12,14,17,18,20|7,1,3,9,5|]; int: res=sum(n,g in 1..5 where n>g)(N[n,g]); output([show(res)])  
http://rosettacode.org/wiki/Sum_and_product_puzzle
Sum and product puzzle
Task[edit] Solve the "Impossible Puzzle": X and Y are two different whole numbers greater than 1. Their sum is no greater than 100, and Y is greater than X. S and P are two mathematicians (and consequently perfect logicians); S knows the sum X+Y and P knows the product X*Y. Both S and P know all the information in this paragraph. The following conversation occurs: S says "P does not know X and Y." P says "Now I know X and Y." S says "Now I also know X and Y!" What are X and Y? Guidance It can be hard to wrap one's head around what the three lines of dialog between S (the "sum guy") and P (the "product guy") convey about the values of X and Y. So for your convenience, here's a break-down: Quote Implied fact 1) S says "P does not know X and Y." For every possible sum decomposition of the number X+Y, the product has in turn more than one product decomposition. 2) P says "Now I know X and Y." The number X*Y has only one product decomposition for which fact 1 is true. 3) S says "Now I also know X and Y." The number X+Y has only one sum decomposition for which fact 2 is true. Terminology: "sum decomposition" of a number = Any pair of positive integers (A, B) so that A+B equals the number. Here, with the additional constraint 2 ≤ A < B. "product decomposition" of a number = Any pair of positive integers (A, B) so that A*B equals the number. Here, with the additional constraint 2 ≤ A < B. Your program can solve the puzzle by considering all possible pairs (X, Y) in the range 2 ≤ X < Y ≤ 98, and then successively eliminating candidates based on the three facts. It turns out only one solution remains! See the Python example for an implementation that uses this approach with a few optimizations. See also   Wikipedia:   Sum and Product Puzzle
#Factor
Factor
USING: combinators.short-circuit fry kernel literals math math.ranges memoize prettyprint sequences sets tools.time ; IN: rosetta-code.sum-and-product   CONSTANT: s1 $[ 2 100 [a,b] dup cartesian-product concat [ first2 { [ < ] [ + 100 < ] } 2&& ] filter ]   : quot-eq ( pair quot -- seq ) [ s1 ] 2dip tuck '[ @ _ @ = ] filter ; inline   MEMO: sum-eq ( pair -- seq ) [ first2 + ] quot-eq ; MEMO: mul-eq ( pair -- seq ) [ first2 * ] quot-eq ;   : s2 ( -- seq ) s1 [ sum-eq [ mul-eq length 1 = not ] all? ] filter ;   : only-1 ( seq quot -- newseq ) over '[ @ _ intersect length 1 = ] filter ; inline   : sum-and-product ( -- ) [ s2 [ mul-eq ] [ sum-eq ] [ only-1 ] bi@ . ] time ;   MAIN: sum-and-product
http://rosettacode.org/wiki/Symmetric_difference
Symmetric difference
Task Given two sets A and B, compute ( A ∖ B ) ∪ ( B ∖ A ) . {\displaystyle (A\setminus B)\cup (B\setminus A).} That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B. In other words: ( A ∪ B ) ∖ ( A ∩ B ) {\displaystyle (A\cup B)\setminus (A\cap B)} (the set of items that are in at least one of A or B minus the set of items that are in both A and B). Optionally, give the individual differences ( A ∖ B {\displaystyle A\setminus B} and B ∖ A {\displaystyle B\setminus A} ) as well. Test cases A = {John, Bob, Mary, Serena} B = {Jim, Mary, John, Bob} Notes If your code uses lists of items to represent sets then ensure duplicate items in lists are correctly handled. For example two lists representing sets of a = ["John", "Serena", "Bob", "Mary", "Serena"] and b = ["Jim", "Mary", "John", "Jim", "Bob"] should produce the result of just two strings: ["Serena", "Jim"], in any order. In the mathematical notation above A \ B gives the set of items in A that are not in B; A ∪ B gives the set of items in both A and B, (their union); and A ∩ B gives the set of items that are in both A and B (their intersection).
#TUSCRIPT
TUSCRIPT
$$ MODE TUSCRIPT a="John'Bob'Mary'Serena" b="Jim'Mary'John'Bob"   DICT names CREATE   SUBMACRO checknames !var,val PRINT val,": ",var LOOP n=var DICT names APPEND/QUIET n,num,cnt,val;" " ENDLOOP ENDSUBMACRO   CALL checknames (a,"a") CALL checknames (b,"b")   DICT names UNLOAD names,num,cnt,val   LOOP n=names,v=val PRINT n," in: ",v ENDLOOP
http://rosettacode.org/wiki/Symmetric_difference
Symmetric difference
Task Given two sets A and B, compute ( A ∖ B ) ∪ ( B ∖ A ) . {\displaystyle (A\setminus B)\cup (B\setminus A).} That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B. In other words: ( A ∪ B ) ∖ ( A ∩ B ) {\displaystyle (A\cup B)\setminus (A\cap B)} (the set of items that are in at least one of A or B minus the set of items that are in both A and B). Optionally, give the individual differences ( A ∖ B {\displaystyle A\setminus B} and B ∖ A {\displaystyle B\setminus A} ) as well. Test cases A = {John, Bob, Mary, Serena} B = {Jim, Mary, John, Bob} Notes If your code uses lists of items to represent sets then ensure duplicate items in lists are correctly handled. For example two lists representing sets of a = ["John", "Serena", "Bob", "Mary", "Serena"] and b = ["Jim", "Mary", "John", "Jim", "Bob"] should produce the result of just two strings: ["Serena", "Jim"], in any order. In the mathematical notation above A \ B gives the set of items in A that are not in B; A ∪ B gives the set of items in both A and B, (their union); and A ∩ B gives the set of items that are in both A and B (their intersection).
#UNIX_Shell
UNIX Shell
uniq() { u=("$@") for ((i=0;i<${#u[@]};i++)); do for ((j=i+1;j<=${#u[@]};j++)); do [ "${u[$i]}" = "${u[$j]}" ] && unset u[$i] done done u=("${u[@]}") }   a=(John Serena Bob Mary Serena) b=(Jim Mary John Jim Bob)   uniq "${a[@]}" au=("${u[@]}") uniq "${b[@]}" bu=("${u[@]}")   ab=("${au[@]}") for ((i=0;i<=${#au[@]};i++)); do for ((j=0;j<=${#bu[@]};j++)); do [ "${ab[$i]}" = "${bu[$j]}" ] && unset ab[$i] done done ab=("${ab[@]}")   ba=("${bu[@]}") for ((i=0;i<=${#bu[@]};i++)); do for ((j=0;j<=${#au[@]};j++)); do [ "${ba[$i]}" = "${au[$j]}" ] && unset ba[$i] done done ba=("${ba[@]}")   sd=("${ab[@]}" "${ba[@]}")   echo "Set A = ${a[@]}" echo " = ${au[@]}" echo "Set B = ${b[@]}" echo " = ${bu[@]}" echo "A - B = ${ab[@]}" echo "B - A = ${ba[@]}" echo "Symmetric difference = ${sd[@]}"
http://rosettacode.org/wiki/Temperature_conversion
Temperature conversion
There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones: Kelvin, Celsius, Fahrenheit, and Rankine. The Celsius and Kelvin scales have the same magnitude, but different null points. 0 degrees Celsius corresponds to 273.15 kelvin. 0 kelvin is absolute zero. The Fahrenheit and Rankine scales also have the same magnitude, but different null points. 0 degrees Fahrenheit corresponds to 459.67 degrees Rankine. 0 degrees Rankine is absolute zero. The Celsius/Kelvin and Fahrenheit/Rankine scales have a ratio of 5 : 9. Task Write code that accepts a value of kelvin, converts it to values of the three other scales, and prints the result. Example K 21.00 C -252.15 F -421.87 R 37.80
#Quackery
Quackery
[ $ "bigrat.qky" loadfile ] now!   [ 5 9 v* ] is r->k ( n/d --> n/d ) [ 1/v r->k 1/v ] is k->r ( n/d --> n/d )   [ 45967 100 v- ] is r->f ( n/d --> n/d ) [ -v r->f -v ] is f->r ( n/d --> n/d )   [ 5463 20 v- ] is k->c ( n/d --> n/d ) [ -v k->c -v ] is c->k ( n/d --> n/d )   [ k->r r->f ] is k->f ( n/d --> n/d ) [ f->r r->k ] is f->k ( n/d --> n/d )   [ r->k k->c ] is r->c ( n/d --> n/d ) [ c->k k->r ] is c->r ( n/d --> n/d )   [ f->k k->c ] is f->c ( n/d --> n/d ) [ c->r r->f ] is c->f ( n/d --> n/d )   [ $->v drop 2dup 10 point$ echo$ say " Kelvins is equal to" cr k->c 2dup 10 point$ echo$ say " degrees Celcius" cr c->f 2dup 10 point$ echo$ say " degrees Fahrenheit" cr f->r 10 point$ echo$ say " degrees Rankine" cr ] is task ( $ --> )   $ "21.00" task
http://rosettacode.org/wiki/Temperature_conversion
Temperature conversion
There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones: Kelvin, Celsius, Fahrenheit, and Rankine. The Celsius and Kelvin scales have the same magnitude, but different null points. 0 degrees Celsius corresponds to 273.15 kelvin. 0 kelvin is absolute zero. The Fahrenheit and Rankine scales also have the same magnitude, but different null points. 0 degrees Fahrenheit corresponds to 459.67 degrees Rankine. 0 degrees Rankine is absolute zero. The Celsius/Kelvin and Fahrenheit/Rankine scales have a ratio of 5 : 9. Task Write code that accepts a value of kelvin, converts it to values of the three other scales, and prints the result. Example K 21.00 C -252.15 F -421.87 R 37.80
#R
R
convert_Kelvin <- function(K){ if (!is.numeric(K)) stop("\n Input has to be numeric")   return(list( Kelvin = K, Celsius = K - 273.15, Fahreneit = K * 1.8 - 459.67, Rankine = K * 1.8 ))   }   convert_Kelvin(21)  
http://rosettacode.org/wiki/System_time
System time
Task Output the system time   (any units will do as long as they are noted) either by a system command or one built into the language. The system time can be used for debugging, network information, random number seeds, or something as simple as program performance. Related task   Date format See also   Retrieving system time (wiki)
#Prolog
Prolog
date_time(H).
http://rosettacode.org/wiki/System_time
System time
Task Output the system time   (any units will do as long as they are noted) either by a system command or one built into the language. The system time can be used for debugging, network information, random number seeds, or something as simple as program performance. Related task   Date format See also   Retrieving system time (wiki)
#PureBasic
PureBasic
time=Date() ; Unix timestamp time$=FormatDate("%mm.%dd.%yyyy %hh:%ii:%ss",time)   ; following value is only reasonable accurate, on Windows it can differ by +/- 20 ms ms_counter=ElapsedMilliseconds() ; could use API like QueryPerformanceCounter_() on Windows for more accurate values
http://rosettacode.org/wiki/Sum_of_elements_below_main_diagonal_of_matrix
Sum of elements below main diagonal of matrix
Task Find and display the sum of elements that are below the main diagonal of a matrix. The matrix should be a square matrix. ───   Matrix to be used:   ─── [[1,3,7,8,10], [2,4,16,14,4], [3,1,9,18,11], [12,14,17,18,20], [7,1,3,9,5]]
#Nim
Nim
type SquareMatrix[T: SomeNumber; N: static Positive] = array[N, array[N, T]]   func sumBelowDiagonal[T, N](m: SquareMatrix[T, N]): T = for i in 1..<N: for j in 0..<i: result += m[i][j]   const M = [[ 1, 3, 7, 8, 10], [ 2, 4, 16, 14, 4], [ 3, 1, 9, 18, 11], [12, 14, 17, 18, 20], [ 7, 1, 3, 9, 5]]   echo sumBelowDiagonal(M)
http://rosettacode.org/wiki/Sum_of_elements_below_main_diagonal_of_matrix
Sum of elements below main diagonal of matrix
Task Find and display the sum of elements that are below the main diagonal of a matrix. The matrix should be a square matrix. ───   Matrix to be used:   ─── [[1,3,7,8,10], [2,4,16,14,4], [3,1,9,18,11], [12,14,17,18,20], [7,1,3,9,5]]
#Perl
Perl
#!/usr/bin/perl   use strict; use warnings; use List::Util qw( sum );   my $matrix = [[1,3,7,8,10], [2,4,16,14,4], [3,1,9,18,11], [12,14,17,18,20], [7,1,3,9,5]];   my $lowersum = sum map @{ $matrix->[$_] }[0 .. $_ - 1], 1 .. $#$matrix; print "lower sum = $lowersum\n";
http://rosettacode.org/wiki/Sum_and_product_puzzle
Sum and product puzzle
Task[edit] Solve the "Impossible Puzzle": X and Y are two different whole numbers greater than 1. Their sum is no greater than 100, and Y is greater than X. S and P are two mathematicians (and consequently perfect logicians); S knows the sum X+Y and P knows the product X*Y. Both S and P know all the information in this paragraph. The following conversation occurs: S says "P does not know X and Y." P says "Now I know X and Y." S says "Now I also know X and Y!" What are X and Y? Guidance It can be hard to wrap one's head around what the three lines of dialog between S (the "sum guy") and P (the "product guy") convey about the values of X and Y. So for your convenience, here's a break-down: Quote Implied fact 1) S says "P does not know X and Y." For every possible sum decomposition of the number X+Y, the product has in turn more than one product decomposition. 2) P says "Now I know X and Y." The number X*Y has only one product decomposition for which fact 1 is true. 3) S says "Now I also know X and Y." The number X+Y has only one sum decomposition for which fact 2 is true. Terminology: "sum decomposition" of a number = Any pair of positive integers (A, B) so that A+B equals the number. Here, with the additional constraint 2 ≤ A < B. "product decomposition" of a number = Any pair of positive integers (A, B) so that A*B equals the number. Here, with the additional constraint 2 ≤ A < B. Your program can solve the puzzle by considering all possible pairs (X, Y) in the range 2 ≤ X < Y ≤ 98, and then successively eliminating candidates based on the three facts. It turns out only one solution remains! See the Python example for an implementation that uses this approach with a few optimizations. See also   Wikipedia:   Sum and Product Puzzle
#Go
Go
package main   import "fmt"   type pair struct{ x, y int }   func main() { //const max = 100 // Use 1685 (the highest with a unique answer) instead // of 100 just to make it work a little harder :). const max = 1685 var all []pair for a := 2; a < max; a++ { for b := a + 1; b < max-a; b++ { all = append(all, pair{a, b}) } } fmt.Println("There are", len(all), "pairs where a+b <", max, "(and a<b)") products := countProducts(all)   // Those for which no sum decomposition has unique product to are // S mathimatician's possible pairs. var sPairs []pair pairs: for _, p := range all { s := p.x + p.y // foreach a+b=s (a<b) for a := 2; a < s/2+s&1; a++ { b := s - a if products[a*b] == 1 { // Excluded because P would have a unique product continue pairs } } sPairs = append(sPairs, p) } fmt.Println("S starts with", len(sPairs), "possible pairs.") //fmt.Println("S pairs:", sPairs) sProducts := countProducts(sPairs)   // Look in sPairs for those with a unique product to get // P mathimatician's possible pairs. var pPairs []pair for _, p := range sPairs { if sProducts[p.x*p.y] == 1 { pPairs = append(pPairs, p) } } fmt.Println("P then has", len(pPairs), "possible pairs.") //fmt.Println("P pairs:", pPairs) pSums := countSums(pPairs)   // Finally, look in pPairs for those with a unique sum var final []pair for _, p := range pPairs { if pSums[p.x+p.y] == 1 { final = append(final, p) } }   // Nicely show any answers. switch len(final) { case 1: fmt.Println("Answer:", final[0].x, "and", final[0].y) case 0: fmt.Println("No possible answer.") default: fmt.Println(len(final), "possible answers:", final) } }   func countProducts(list []pair) map[int]int { m := make(map[int]int) for _, p := range list { m[p.x*p.y]++ } return m }   func countSums(list []pair) map[int]int { m := make(map[int]int) for _, p := range list { m[p.x+p.y]++ } return m }   // not used, manually inlined above func decomposeSum(s int) []pair { pairs := make([]pair, 0, s/2) for a := 2; a < s/2+s&1; a++ { pairs = append(pairs, pair{a, s - a}) } return pairs }
http://rosettacode.org/wiki/Symmetric_difference
Symmetric difference
Task Given two sets A and B, compute ( A ∖ B ) ∪ ( B ∖ A ) . {\displaystyle (A\setminus B)\cup (B\setminus A).} That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B. In other words: ( A ∪ B ) ∖ ( A ∩ B ) {\displaystyle (A\cup B)\setminus (A\cap B)} (the set of items that are in at least one of A or B minus the set of items that are in both A and B). Optionally, give the individual differences ( A ∖ B {\displaystyle A\setminus B} and B ∖ A {\displaystyle B\setminus A} ) as well. Test cases A = {John, Bob, Mary, Serena} B = {Jim, Mary, John, Bob} Notes If your code uses lists of items to represent sets then ensure duplicate items in lists are correctly handled. For example two lists representing sets of a = ["John", "Serena", "Bob", "Mary", "Serena"] and b = ["Jim", "Mary", "John", "Jim", "Bob"] should produce the result of just two strings: ["Serena", "Jim"], in any order. In the mathematical notation above A \ B gives the set of items in A that are not in B; A ∪ B gives the set of items in both A and B, (their union); and A ∩ B gives the set of items that are in both A and B (their intersection).
#Ursala
Ursala
a = <'John','Bob','Mary','Serena'> b = <'Jim','Mary','John','Bob'>   #cast %sLm   main =   < 'a': a, 'b': b, 'a not b': ~&j/a b, 'b not a': ~&j/b a, 'symmetric difference': ~&jrljTs/a b>
http://rosettacode.org/wiki/Symmetric_difference
Symmetric difference
Task Given two sets A and B, compute ( A ∖ B ) ∪ ( B ∖ A ) . {\displaystyle (A\setminus B)\cup (B\setminus A).} That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B. In other words: ( A ∪ B ) ∖ ( A ∩ B ) {\displaystyle (A\cup B)\setminus (A\cap B)} (the set of items that are in at least one of A or B minus the set of items that are in both A and B). Optionally, give the individual differences ( A ∖ B {\displaystyle A\setminus B} and B ∖ A {\displaystyle B\setminus A} ) as well. Test cases A = {John, Bob, Mary, Serena} B = {Jim, Mary, John, Bob} Notes If your code uses lists of items to represent sets then ensure duplicate items in lists are correctly handled. For example two lists representing sets of a = ["John", "Serena", "Bob", "Mary", "Serena"] and b = ["Jim", "Mary", "John", "Jim", "Bob"] should produce the result of just two strings: ["Serena", "Jim"], in any order. In the mathematical notation above A \ B gives the set of items in A that are not in B; A ∪ B gives the set of items in both A and B, (their union); and A ∩ B gives the set of items that are in both A and B (their intersection).
#Wren
Wren
import "/set" for Set   var symmetricDifference = Fn.new { |a, b| a.except(b).union(b.except(a)) }   var a = Set.new(["John", "Bob", "Mary", "Serena"]) var b = Set.new(["Jim", "Mary", "John", "Bob"]) System.print("A = %(a)") System.print("B = %(b)") System.print("A - B = %(a.except(b))") System.print("B - A = %(b.except(a))") System.print("A △ B = %(symmetricDifference.call(a, b))")
http://rosettacode.org/wiki/Temperature_conversion
Temperature conversion
There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones: Kelvin, Celsius, Fahrenheit, and Rankine. The Celsius and Kelvin scales have the same magnitude, but different null points. 0 degrees Celsius corresponds to 273.15 kelvin. 0 kelvin is absolute zero. The Fahrenheit and Rankine scales also have the same magnitude, but different null points. 0 degrees Fahrenheit corresponds to 459.67 degrees Rankine. 0 degrees Rankine is absolute zero. The Celsius/Kelvin and Fahrenheit/Rankine scales have a ratio of 5 : 9. Task Write code that accepts a value of kelvin, converts it to values of the three other scales, and prints the result. Example K 21.00 C -252.15 F -421.87 R 37.80
#Racket
Racket
#lang racket (define (converter temp init final) (define to-k (case init ('k temp) ('c (+ 273.15 temp)) ('f (* (+ temp 459.67) 5/9)) ('r (* temp 5/9)))) (case final ('k to-k) ('c (- to-k 273.15)) ('f (- (* to-k 9/5) 459.67)) ('r (* to-k 1.8))))   (define (kelvin-to-all temp) (display (format "Kelvin: ~a \nCelsius: ~a \nFahrenheit: ~a \nRankine: ~a \n" temp (converter temp 'k 'c) (converter temp 'k 'f) (converter temp 'k 'r)))) (kelvin-to-all 21) ;Kelvin: 21 ;Celsius: -252.14999999999998 ;Fahrenheit: -421.87 ;Rankine: 37.800000000000004  
http://rosettacode.org/wiki/Temperature_conversion
Temperature conversion
There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones: Kelvin, Celsius, Fahrenheit, and Rankine. The Celsius and Kelvin scales have the same magnitude, but different null points. 0 degrees Celsius corresponds to 273.15 kelvin. 0 kelvin is absolute zero. The Fahrenheit and Rankine scales also have the same magnitude, but different null points. 0 degrees Fahrenheit corresponds to 459.67 degrees Rankine. 0 degrees Rankine is absolute zero. The Celsius/Kelvin and Fahrenheit/Rankine scales have a ratio of 5 : 9. Task Write code that accepts a value of kelvin, converts it to values of the three other scales, and prints the result. Example K 21.00 C -252.15 F -421.87 R 37.80
#Raku
Raku
my %scale = Celcius => { factor => 1 , offset => -273.15 }, Rankine => { factor => 1.8, offset => 0 }, Fahrenheit => { factor => 1.8, offset => -459.67 }, ;   my $kelvin = +prompt "Enter a temperature in Kelvin: "; die "No such temperature!" if $kelvin < 0;   for %scale.sort { printf "%12s: %7.2f\n", .key, $kelvin * .value<factor> + .value<offset>; }
http://rosettacode.org/wiki/System_time
System time
Task Output the system time   (any units will do as long as they are noted) either by a system command or one built into the language. The system time can be used for debugging, network information, random number seeds, or something as simple as program performance. Related task   Date format See also   Retrieving system time (wiki)
#Python
Python
import time print time.ctime()
http://rosettacode.org/wiki/System_time
System time
Task Output the system time   (any units will do as long as they are noted) either by a system command or one built into the language. The system time can be used for debugging, network information, random number seeds, or something as simple as program performance. Related task   Date format See also   Retrieving system time (wiki)
#Q
Q
q).z.D 2010.01.25 q).z.N 0D14:17:45.519682000 q).z.P 2010.01.25D14:17:46.962375000 q).z.T 14:17:47.817 q).z.Z 2010.01.25T14:17:48.711 q).z.z 2010.01.25T19:17:59.445
http://rosettacode.org/wiki/Sum_of_elements_below_main_diagonal_of_matrix
Sum of elements below main diagonal of matrix
Task Find and display the sum of elements that are below the main diagonal of a matrix. The matrix should be a square matrix. ───   Matrix to be used:   ─── [[1,3,7,8,10], [2,4,16,14,4], [3,1,9,18,11], [12,14,17,18,20], [7,1,3,9,5]]
#Phix
Phix
constant M = {{ 1, 3, 7, 8, 10}, { 2, 4, 16, 14, 4}, { 3, 1, 9, 18, 11}, {12, 14, 17, 18, 20}, { 7, 1, 3, 9, 5}} atom res = 0 integer height = length(M) for row=1 to height do integer width = length(M[row]) if width!=height then crash("not square") end if for col=1 to row-1 do res += M[row][col] end for end for ?res
http://rosettacode.org/wiki/Sum_and_product_puzzle
Sum and product puzzle
Task[edit] Solve the "Impossible Puzzle": X and Y are two different whole numbers greater than 1. Their sum is no greater than 100, and Y is greater than X. S and P are two mathematicians (and consequently perfect logicians); S knows the sum X+Y and P knows the product X*Y. Both S and P know all the information in this paragraph. The following conversation occurs: S says "P does not know X and Y." P says "Now I know X and Y." S says "Now I also know X and Y!" What are X and Y? Guidance It can be hard to wrap one's head around what the three lines of dialog between S (the "sum guy") and P (the "product guy") convey about the values of X and Y. So for your convenience, here's a break-down: Quote Implied fact 1) S says "P does not know X and Y." For every possible sum decomposition of the number X+Y, the product has in turn more than one product decomposition. 2) P says "Now I know X and Y." The number X*Y has only one product decomposition for which fact 1 is true. 3) S says "Now I also know X and Y." The number X+Y has only one sum decomposition for which fact 2 is true. Terminology: "sum decomposition" of a number = Any pair of positive integers (A, B) so that A+B equals the number. Here, with the additional constraint 2 ≤ A < B. "product decomposition" of a number = Any pair of positive integers (A, B) so that A*B equals the number. Here, with the additional constraint 2 ≤ A < B. Your program can solve the puzzle by considering all possible pairs (X, Y) in the range 2 ≤ X < Y ≤ 98, and then successively eliminating candidates based on the three facts. It turns out only one solution remains! See the Python example for an implementation that uses this approach with a few optimizations. See also   Wikipedia:   Sum and Product Puzzle
#Haskell
Haskell
import Data.List (intersect)   s1, s2, s3, s4 :: [(Int, Int)] s1 = [(x, y) | x <- [1 .. 100], y <- [1 .. 100], 1 < x && x < y && x + y < 100]   add, mul :: (Int, Int) -> Int add (x, y) = x + y mul (x, y) = x * y   sumEq, mulEq :: (Int, Int) -> [(Int, Int)] sumEq p = filter (\q -> add q == add p) s1 mulEq p = filter (\q -> mul q == mul p) s1   s2 = filter (\p -> all (\q -> (length $ mulEq q) /= 1) (sumEq p)) s1 s3 = filter (\p -> length (mulEq p `intersect` s2) == 1) s2 s4 = filter (\p -> length (sumEq p `intersect` s3) == 1) s3   main = print s4
http://rosettacode.org/wiki/Symmetric_difference
Symmetric difference
Task Given two sets A and B, compute ( A ∖ B ) ∪ ( B ∖ A ) . {\displaystyle (A\setminus B)\cup (B\setminus A).} That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B. In other words: ( A ∪ B ) ∖ ( A ∩ B ) {\displaystyle (A\cup B)\setminus (A\cap B)} (the set of items that are in at least one of A or B minus the set of items that are in both A and B). Optionally, give the individual differences ( A ∖ B {\displaystyle A\setminus B} and B ∖ A {\displaystyle B\setminus A} ) as well. Test cases A = {John, Bob, Mary, Serena} B = {Jim, Mary, John, Bob} Notes If your code uses lists of items to represent sets then ensure duplicate items in lists are correctly handled. For example two lists representing sets of a = ["John", "Serena", "Bob", "Mary", "Serena"] and b = ["Jim", "Mary", "John", "Jim", "Bob"] should produce the result of just two strings: ["Serena", "Jim"], in any order. In the mathematical notation above A \ B gives the set of items in A that are not in B; A ∪ B gives the set of items in both A and B, (their union); and A ∩ B gives the set of items that are in both A and B (their intersection).
#XPL0
XPL0
def John, Bob, Mary, Serena, Jim; \enumerate set items (0..4)   proc SetOut(S); \Output the elements in set int S; int Name, I; [Name:= ["John", "Bob", "Mary", "Serena", "Jim"]; for I:= 0 to 31 do if S & 1<<I then [Text(0, Name(I)); ChOut(0, ^ )]; CrLf(0); ];   int A, B; [A:= 1<<John ! 1<<Bob ! 1<<Mary ! 1<<Serena; B:= 1<<Jim ! 1<<Mary ! 1<<John ! 1<<Bob; Text(0, "A xor B = "); SetOut(A | B); Text(0, "A\B = "); SetOut(A & ~B); Text(0, "B\A = "); SetOut(B & ~A); Text(0, "A\B U B\A = "); SetOut(A&~B ! B&~A); ]
http://rosettacode.org/wiki/Symmetric_difference
Symmetric difference
Task Given two sets A and B, compute ( A ∖ B ) ∪ ( B ∖ A ) . {\displaystyle (A\setminus B)\cup (B\setminus A).} That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B. In other words: ( A ∪ B ) ∖ ( A ∩ B ) {\displaystyle (A\cup B)\setminus (A\cap B)} (the set of items that are in at least one of A or B minus the set of items that are in both A and B). Optionally, give the individual differences ( A ∖ B {\displaystyle A\setminus B} and B ∖ A {\displaystyle B\setminus A} ) as well. Test cases A = {John, Bob, Mary, Serena} B = {Jim, Mary, John, Bob} Notes If your code uses lists of items to represent sets then ensure duplicate items in lists are correctly handled. For example two lists representing sets of a = ["John", "Serena", "Bob", "Mary", "Serena"] and b = ["Jim", "Mary", "John", "Jim", "Bob"] should produce the result of just two strings: ["Serena", "Jim"], in any order. In the mathematical notation above A \ B gives the set of items in A that are not in B; A ∪ B gives the set of items in both A and B, (their union); and A ∩ B gives the set of items that are in both A and B (their intersection).
#Yabasic
Yabasic
lista1$ = "John Serena Bob Mary Serena" lista2$ = "Jim Mary John Jim Bob"   lista1$ = quitadup$(lista1$) lista2$ = quitadup$(lista2$) res$ = quitacomun$(lista1$, lista2$) res$ = res$ + quitacomun$(lista2$, lista1$) print res$     sub quitadup$(l$) l$ = l$ + " " return quitarep$(l$) end sub     sub quitacomun$(l1$, l2$) l1$ = l1$ + " " l2$ = l2$ + " " return quitarep$(l1$, l2$) end sub     sub quitarep$(l1$, l2$) local pos, n, x, listar$, nombre$, largo   largo = len(l1$) pos = 1 while(true) n = instr(l1$, " ", pos) if n > 0 then nombre$ = mid$(l1$, pos, n-pos) if numparams = 1 then x = instr(listar$, nombre$) else x = instr(l2$, nombre$) end if if x = 0 listar$ = listar$ + nombre$ + " " pos = n + 1 else return listar$ end if wend end sub  
http://rosettacode.org/wiki/Temperature_conversion
Temperature conversion
There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones: Kelvin, Celsius, Fahrenheit, and Rankine. The Celsius and Kelvin scales have the same magnitude, but different null points. 0 degrees Celsius corresponds to 273.15 kelvin. 0 kelvin is absolute zero. The Fahrenheit and Rankine scales also have the same magnitude, but different null points. 0 degrees Fahrenheit corresponds to 459.67 degrees Rankine. 0 degrees Rankine is absolute zero. The Celsius/Kelvin and Fahrenheit/Rankine scales have a ratio of 5 : 9. Task Write code that accepts a value of kelvin, converts it to values of the three other scales, and prints the result. Example K 21.00 C -252.15 F -421.87 R 37.80
#REXX
REXX
/*REXX program converts temperatures for a number (8) of temperature scales. */ numeric digits 120 /*be able to support some huge numbers.*/ parse arg tList /*get the specified temperature list. */   do until tList='' /*process the list of temperatures. */ parse var tList x ',' tList /*temps are separated by commas. */ x= translate(x, '((', "[{") /*support other grouping symbols. */ x= space(x); parse var x z '(' /*handle any comments (if any). */ parse upper var z z ' TO '  ! . /*separate the TO option from number.*/ if !=='' then != 'ALL'; all= !=='ALL' /*allow specification of "TO" opt*/ if z=='' then call serr "no arguments were specified." /*oops-ay. */ _= verify(z, '+-.0123456789') /*list of valid numeral/number thingys.*/ n= z if _\==0 then do if _==1 then call serr 'illegal temperature:' z n= left(z, _ - 1) /*pick off the number (hopefully). */ u= strip( substr(z, _) ) /*pick off the temperature unit. */ end else u= 'k' /*assume kelvin as per task requirement*/   if \datatype(n, 'N') then call serr 'illegal number:' n if \all then do /*is there is a TO ααα scale? */ call name ! /*process the TO abbreviation. */  != s n /*assign the full name to  ! */ end /*!: now contains temperature full name*/ call name u /*allow alternate scale (miss)spellings*/   select /*convert ──► °Fahrenheit temperatures.*/ when sn=='CELSIUS' then F= n * 9/5 + 32 when sn=='DELISLE' then F= 212 -(n * 6/5) when sn=='FAHRENHEIT' then F= n when sn=='KELVIN' then F= n * 9/5 - 459.67 when sn=='NEWTON' then F= n * 60/11 + 32 when sn=='RANKINE' then F= n - 459.67 /*a single R is taken as Rankine.*/ when sn=='REAUMUR' then F= n * 9/4 + 32 when sn=='ROMER' then F= (n-7.5) * 27/4 + 32 otherwise call serr 'illegal temperature scale: ' u end /*select*/   K = (F + 459.67) * 5/9 /*compute temperature to kelvins. */ say right(' ' x, 79, "─") /*show the original value, scale, sep. */ if all | !=='CELSIUS' then say $( ( F - 32 ) * 5/9 ) 'Celsius' if all | !=='DELISLE' then say $( ( 212 - F ) * 5/6 ) 'Delisle' if all | !=='FAHRENHEIT' then say $( F ) 'Fahrenheit' if all | !=='KELVIN' then say $( K ) 'kelvin's(K) if all | !=='NEWTON' then say $( ( F - 32 ) * 11/60 ) 'Newton' if all | !=='RANKINE' then say $( F + 459.67 ) 'Rankine' if all | !=='REAUMUR' then say $( ( F - 32 ) * 4/9 ) 'Reaumur' if all | !=='ROMER' then say $( ( F - 32 ) * 4/27 + 7.5 ) 'Romer' end /*until*/   exit /*stick a fork in it, we're all done. */ /*──────────────────────────────────────────────────────────────────────────────────────*/ s: if arg(1)==1 then return arg(3); return word( arg(2) 's', 1) serr: say; say '***error!***'; say; say arg(1); say; exit 13 /*──────────────────────────────────────────────────────────────────────────────────────*/ $: procedure; showDig= 8 /*only show eight significant digits.*/ _= format( arg(1), , showDig) / 1 /*format number 8 digs past dec, point.*/ p= pos(., _); L= length(_) /*find position of the decimal point. */ /* [↓] align integers with FP numbers.*/ if p==0 then _= _ || left('', 5+showDig+1) /*the number has no decimal point. */ else _= _ || left('', 5+showDig-L+p) /* " " " a " " */ return right(_, 50) /*return the re-formatted number (arg).*/ /*──────────────────────────────────────────────────────────────────────────────────────*/ name: parse arg y /*abbreviations ──► shortname.*/ yU= translate(y, 'eE', "éÉ"); upper yU /*uppercase the temperature unit*/ if left(yU, 7)=='DEGREES' then yU= substr(yU, 8) /*redundant "degrees" after #? */ if left(yU, 6)=='DEGREE' then yU= substr(yU, 7) /* " "degree" " " */ yU= strip(yU) /*elide blanks at front and back*/ _= length(yU) /*obtain the yU length. */ if right(yU,1)=='S' & _>1 then yU= left(yU, _-1) /*elide trailing plural, if any.*/   select /*abbreviations ──► shortname.*/ when abbrev('CENTIGRADE' , yU) |, abbrev('CENTRIGRADE', yU) |, /* 50% misspelled.*/ abbrev('CETIGRADE' , yU) |, /* 50% misspelled.*/ abbrev('CENTINGRADE', yU) |, abbrev('CENTESIMAL' , yU) |, abbrev('CELCIU' , yU) |, /* 82% misspelled.*/ abbrev('CELCIOU' , yU) |, /* 4% misspelled.*/ abbrev('CELCUI' , yU) |, /* 4% misspelled.*/ abbrev('CELSUI' , yU) |, /* 2% misspelled.*/ abbrev('CELCEU' , yU) |, /* 2% misspelled.*/ abbrev('CELCU' , yU) |, /* 2% misspelled.*/ abbrev('CELISU' , yU) |, /* 1% misspelled.*/ abbrev('CELSU' , yU) |, /* 1% misspelled.*/ abbrev('CELSIU' , yU) then sn= 'CELSIUS' when abbrev('DELISLE' , yU,2) then sn= 'DELISLE' when abbrev('FARENHEIT' , yU) |, /* 39% misspelled.*/ abbrev('FARENHEIGHT', yU) |, /* 15% misspelled.*/ abbrev('FARENHITE' , yU) |, /* 6% misspelled.*/ abbrev('FARENHIET' , yU) |, /* 3% misspelled.*/ abbrev('FARHENHEIT' , yU) |, /* 3% misspelled.*/ abbrev('FARINHEIGHT', yU) |, /* 2% misspelled.*/ abbrev('FARENHIGHT' , yU) |, /* 2% misspelled.*/ abbrev('FAHRENHIET' , yU) |, /* 2% misspelled.*/ abbrev('FERENHEIGHT', yU) |, /* 2% misspelled.*/ abbrev('FEHRENHEIT' , yU) |, /* 2% misspelled.*/ abbrev('FERENHEIT' , yU) |, /* 2% misspelled.*/ abbrev('FERINHEIGHT', yU) |, /* 1% misspelled.*/ abbrev('FARIENHEIT' , yU) |, /* 1% misspelled.*/ abbrev('FARINHEIT' , yU) |, /* 1% misspelled.*/ abbrev('FARANHITE' , yU) |, /* 1% misspelled.*/ abbrev('FAHRENHEIT' , yU) then sn= 'FAHRENHEIT' when abbrev('KALVIN' , yU) |, /* 27% misspelled.*/ abbrev('KERLIN' , yU) |, /* 18% misspelled.*/ abbrev('KEVEN' , yU) |, /* 9% misspelled.*/ abbrev('KELVIN' , yU) then sn= 'KELVIN' when abbrev('NEUTON' , yU) |, /*100% misspelled.*/ abbrev('NEWTON' , yU) then sn= 'NEWTON' when abbrev('RANKINE' , yU, 1) then sn= 'RANKINE' when abbrev('REAUMUR' , yU, 2) then sn= 'REAUMUR' when abbrev('ROEMER' , yU, 2) |, abbrev('ROMER' , yU, 2) then sn= 'ROMER' otherwise call serr 'illegal temperature scale:' y end /*select*/ return
http://rosettacode.org/wiki/System_time
System time
Task Output the system time   (any units will do as long as they are noted) either by a system command or one built into the language. The system time can be used for debugging, network information, random number seeds, or something as simple as program performance. Related task   Date format See also   Retrieving system time (wiki)
#Quackery
Quackery
time 1000000 / echo say " seconds since the Unix epoch."
http://rosettacode.org/wiki/System_time
System time
Task Output the system time   (any units will do as long as they are noted) either by a system command or one built into the language. The system time can be used for debugging, network information, random number seeds, or something as simple as program performance. Related task   Date format See also   Retrieving system time (wiki)
#R
R
Sys.time()
http://rosettacode.org/wiki/Sum_of_elements_below_main_diagonal_of_matrix
Sum of elements below main diagonal of matrix
Task Find and display the sum of elements that are below the main diagonal of a matrix. The matrix should be a square matrix. ───   Matrix to be used:   ─── [[1,3,7,8,10], [2,4,16,14,4], [3,1,9,18,11], [12,14,17,18,20], [7,1,3,9,5]]
#PL.2FI
PL/I
  trap: procedure options (main); /* 17 December 2021 */ declare n fixed binary; get (n); put ('The order of the matrix is ' || trim(n)); begin; declare A (n,n) fixed binary; declare sum fixed binary; declare (i, j) fixed binary;   get (A); sum = 0; do i = 2 to n; do j = 1 to i-1; sum = sum + a(i,j); end; end; put edit (A) (skip, (n) f(4) ); put skip data (sum); end; end trap;  
http://rosettacode.org/wiki/Sum_of_elements_below_main_diagonal_of_matrix
Sum of elements below main diagonal of matrix
Task Find and display the sum of elements that are below the main diagonal of a matrix. The matrix should be a square matrix. ───   Matrix to be used:   ─── [[1,3,7,8,10], [2,4,16,14,4], [3,1,9,18,11], [12,14,17,18,20], [7,1,3,9,5]]
#PL.2FM
PL/M
100H: /* SUM THE ELEMENTS BELOW THE MAIN DIAGONAL OF A MATRIX */   /* CP/M BDOS SYSTEM CALL, IGNORE THE RETURN VALUE */ BDOS: PROCEDURE( FN, ARG ); DECLARE FN BYTE, ARG ADDRESS; GOTO 5; END; PR$STRING: PROCEDURE( S ); DECLARE S ADDRESS; CALL BDOS( 9, S ); END; PR$NUMBER: PROCEDURE( N ); /* PRINTS A NUMBER IN THE MINIMUN FIELD WIDTH */ DECLARE N ADDRESS; DECLARE V ADDRESS, N$STR ( 6 )BYTE, W BYTE; V = N; W = LAST( N$STR ); N$STR( W ) = '$'; N$STR( W := W - 1 ) = '0' + ( V MOD 10 ); DO WHILE( ( V := V / 10 ) > 0 ); N$STR( W := W - 1 ) = '0' + ( V MOD 10 ); END; CALL PR$STRING( .N$STR( W ) ); END PR$NUMBER;   /* RETURNS THE SUM OF THE ELEMENTS BELOW THE MAIN DIAGONAL OF MX */ /* MX WOULD BE DECLARED AS ''( UB, UB )ADDRESS'' IF PL/M SUPPORTED */ /* 2-DIMENSIONAL ARRAYS, IT DOESN'T SO MX MUST ACTULLY BE DECLARED */ /* ''( UB * UB )ADDRESS'' - EXCEPT THE BOUND MUST BE A CONSTANT, NOT AN */ /* EXPRESSION */ /* NOTE ''ADDRESS'' MEANS UNSIGNED 16-BIT QUANTITY, WHICH CAN BE USED FOR */ /* OTHER PURPOSES THAN JUST POINTERS */ LOWER$SUM: PROCEDURE( MX, UB )ADDRESS; DECLARE ( MX, UB ) ADDRESS; DECLARE ( SUM, R, C, STRIDE, R$PTR ) ADDRESS; DECLARE M$PTR ADDRESS, M$VALUE BASED M$PTR ADDRESS; SUM = 0; STRIDE = UB + UB; R$PTR = MX + STRIDE; /* ADDRESS OF ROW 1 ( THE FIRST ROW IS 0 ) */ DO R = 1 TO UB - 1; M$PTR = R$PTR; DO C = 0 TO R - 1; SUM = SUM + M$VALUE; M$PTR = M$PTR + 2; END; R$PTR = R$PTR + STRIDE; /* ADDRESS OF THE NEXT ROW */ END; RETURN SUM; END LOWER$SUM ;   /* TASK TEST CASE */ DECLARE T ( 25 )ADDRESS INITIAL( 1, 3, 7, 8, 10 , 2, 4, 16, 14, 4 , 3, 1, 9, 18, 11 , 12, 14, 17, 18, 20 , 7, 1, 3, 9, 5 ); CALL PR$NUMBER( LOWER$SUM( .T, 5 ) );   EOF
http://rosettacode.org/wiki/Sum_and_product_puzzle
Sum and product puzzle
Task[edit] Solve the "Impossible Puzzle": X and Y are two different whole numbers greater than 1. Their sum is no greater than 100, and Y is greater than X. S and P are two mathematicians (and consequently perfect logicians); S knows the sum X+Y and P knows the product X*Y. Both S and P know all the information in this paragraph. The following conversation occurs: S says "P does not know X and Y." P says "Now I know X and Y." S says "Now I also know X and Y!" What are X and Y? Guidance It can be hard to wrap one's head around what the three lines of dialog between S (the "sum guy") and P (the "product guy") convey about the values of X and Y. So for your convenience, here's a break-down: Quote Implied fact 1) S says "P does not know X and Y." For every possible sum decomposition of the number X+Y, the product has in turn more than one product decomposition. 2) P says "Now I know X and Y." The number X*Y has only one product decomposition for which fact 1 is true. 3) S says "Now I also know X and Y." The number X+Y has only one sum decomposition for which fact 2 is true. Terminology: "sum decomposition" of a number = Any pair of positive integers (A, B) so that A+B equals the number. Here, with the additional constraint 2 ≤ A < B. "product decomposition" of a number = Any pair of positive integers (A, B) so that A*B equals the number. Here, with the additional constraint 2 ≤ A < B. Your program can solve the puzzle by considering all possible pairs (X, Y) in the range 2 ≤ X < Y ≤ 98, and then successively eliminating candidates based on the three facts. It turns out only one solution remains! See the Python example for an implementation that uses this approach with a few optimizations. See also   Wikipedia:   Sum and Product Puzzle
#Java
Java
package org.rosettacode;   import java.util.ArrayList; import java.util.List;     /** * This program applies the logic in the Sum and Product Puzzle for the value * provided by systematically applying each requirement to all number pairs in * range. Note that the requirements: (x, y different), (x < y), and * (x, y > MIN_VALUE) are baked into the loops in run(), sumAddends(), and * productFactors(), so do not need a separate test. Also note that to test a * solution to this logic puzzle, it is suggested to test the condition with * maxSum = 1685 to ensure that both the original solution (4, 13) and the * additional solution (4, 61), and only these solutions, are found. Note * also that at 1684 only the original solution should be found! */ public class SumAndProductPuzzle { private final long beginning; private final int maxSum; private static final int MIN_VALUE = 2; private List<int[]> firstConditionExcludes = new ArrayList<>(); private List<int[]> secondConditionExcludes = new ArrayList<>();   public static void main(String... args){   if (args.length == 0){ new SumAndProductPuzzle(100).run(); new SumAndProductPuzzle(1684).run(); new SumAndProductPuzzle(1685).run(); } else { for (String arg : args){ try{ new SumAndProductPuzzle(Integer.valueOf(arg)).run(); } catch (NumberFormatException e){ System.out.println("Please provide only integer arguments. " + "Provided argument " + arg + " was not an integer. " + "Alternatively, calling the program with no arguments " + "will run the puzzle where maximum sum equals 100, 1684, and 1865."); } } } }   public SumAndProductPuzzle(int maxSum){ this.beginning = System.currentTimeMillis(); this.maxSum = maxSum; System.out.println("Run with maximum sum of " + String.valueOf(maxSum) + " started at " + String.valueOf(beginning) + "."); }   public void run(){ for (int x = MIN_VALUE; x < maxSum - MIN_VALUE; x++){ for (int y = x + 1; y < maxSum - MIN_VALUE; y++){   if (isSumNoGreaterThanMax(x,y) && isSKnowsPCannotKnow(x,y) && isPKnowsNow(x,y) && isSKnowsNow(x,y) ){ System.out.println("Found solution x is " + String.valueOf(x) + " y is " + String.valueOf(y) + " in " + String.valueOf(System.currentTimeMillis() - beginning) + "ms."); } } } System.out.println("Run with maximum sum of " + String.valueOf(maxSum) + " ended in " + String.valueOf(System.currentTimeMillis() - beginning) + "ms."); }   public boolean isSumNoGreaterThanMax(int x, int y){ return x + y <= maxSum; }   public boolean isSKnowsPCannotKnow(int x, int y){   if (firstConditionExcludes.contains(new int[] {x, y})){ return false; }   for (int[] addends : sumAddends(x, y)){ if ( !(productFactors(addends[0], addends[1]).size() > 1) ) { firstConditionExcludes.add(new int[] {x, y}); return false; } } return true; }   public boolean isPKnowsNow(int x, int y){   if (secondConditionExcludes.contains(new int[] {x, y})){ return false; }   int countSolutions = 0; for (int[] factors : productFactors(x, y)){ if (isSKnowsPCannotKnow(factors[0], factors[1])){ countSolutions++; } }   if (countSolutions == 1){ return true; } else { secondConditionExcludes.add(new int[] {x, y}); return false; } }   public boolean isSKnowsNow(int x, int y){   int countSolutions = 0; for (int[] addends : sumAddends(x, y)){ if (isPKnowsNow(addends[0], addends[1])){ countSolutions++; } } return countSolutions == 1; }   public List<int[]> sumAddends(int x, int y){   List<int[]> list = new ArrayList<>(); int sum = x + y;   for (int addend = MIN_VALUE; addend < sum - addend; addend++){ if (isSumNoGreaterThanMax(addend, sum - addend)){ list.add(new int[]{addend, sum - addend}); } } return list; }   public List<int[]> productFactors(int x, int y){   List<int[]> list = new ArrayList<>(); int product = x * y;   for (int factor = MIN_VALUE; factor < product / factor; factor++){ if (product % factor == 0){ if (isSumNoGreaterThanMax(factor, product / factor)){ list.add(new int[]{factor, product / factor}); } } } return list; } }
http://rosettacode.org/wiki/Symmetric_difference
Symmetric difference
Task Given two sets A and B, compute ( A ∖ B ) ∪ ( B ∖ A ) . {\displaystyle (A\setminus B)\cup (B\setminus A).} That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B. In other words: ( A ∪ B ) ∖ ( A ∩ B ) {\displaystyle (A\cup B)\setminus (A\cap B)} (the set of items that are in at least one of A or B minus the set of items that are in both A and B). Optionally, give the individual differences ( A ∖ B {\displaystyle A\setminus B} and B ∖ A {\displaystyle B\setminus A} ) as well. Test cases A = {John, Bob, Mary, Serena} B = {Jim, Mary, John, Bob} Notes If your code uses lists of items to represent sets then ensure duplicate items in lists are correctly handled. For example two lists representing sets of a = ["John", "Serena", "Bob", "Mary", "Serena"] and b = ["Jim", "Mary", "John", "Jim", "Bob"] should produce the result of just two strings: ["Serena", "Jim"], in any order. In the mathematical notation above A \ B gives the set of items in A that are not in B; A ∪ B gives the set of items in both A and B, (their union); and A ∩ B gives the set of items that are in both A and B (their intersection).
#zkl
zkl
fcn setCommon(list1,list2){ list1.filter(list2.holds); } fcn sdiff(list1,list2) { list1.extend(list2).copy().removeEach(setCommon(list1,list2)) }
http://rosettacode.org/wiki/Temperature_conversion
Temperature conversion
There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones: Kelvin, Celsius, Fahrenheit, and Rankine. The Celsius and Kelvin scales have the same magnitude, but different null points. 0 degrees Celsius corresponds to 273.15 kelvin. 0 kelvin is absolute zero. The Fahrenheit and Rankine scales also have the same magnitude, but different null points. 0 degrees Fahrenheit corresponds to 459.67 degrees Rankine. 0 degrees Rankine is absolute zero. The Celsius/Kelvin and Fahrenheit/Rankine scales have a ratio of 5 : 9. Task Write code that accepts a value of kelvin, converts it to values of the three other scales, and prints the result. Example K 21.00 C -252.15 F -421.87 R 37.80
#Ring
Ring
  k = 21.0 c = 0 r = 0 f = 0 convertTemp(k) see "Kelvin : " + k + nl + "Celcius : " + c + nl + "Rankine : " + r + nl + "Fahrenheit : " + f + nl   func convertTemp k c = k - 273.15 r = k * 1.8 f = r - 459.67  
http://rosettacode.org/wiki/System_time
System time
Task Output the system time   (any units will do as long as they are noted) either by a system command or one built into the language. The system time can be used for debugging, network information, random number seeds, or something as simple as program performance. Related task   Date format See also   Retrieving system time (wiki)
#Racket
Racket
#lang racket (require racket/date) (date->string (current-date))