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<html><head><title>dlib C++ Library - disjoint_subsets_abstract.h</title></head><body bgcolor='white'><pre> |
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<font color='#009900'>// Copyright (C) 2011 Davis E. King ([email protected]) |
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</font><font color='#009900'>// License: Boost Software License See LICENSE.txt for the full license. |
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</font><font color='#0000FF'>#undef</font> DLIB_DISJOINT_SUBsETS_ABSTRACT_Hh_ |
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<font color='#0000FF'>#ifdef</font> DLIB_DISJOINT_SUBsETS_ABSTRACT_Hh_ |
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<font color='#0000FF'>#include</font> <font color='#5555FF'><</font>vector<font color='#5555FF'>></font> |
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<font color='#0000FF'>#include</font> "<a style='text-decoration:none' href='../algs.h.html'>../algs.h</a>" |
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<font color='#0000FF'>namespace</font> dlib |
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<b>{</b> |
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<font color='#009900'>// ---------------------------------------------------------------------------------------- |
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</font> |
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<font color='#0000FF'>class</font> <b><a name='disjoint_subsets'></a>disjoint_subsets</b> |
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<b>{</b> |
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<font color='#009900'>/*! |
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INITIAL VALUE |
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- size() == 0 |
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WHAT THIS OBJECT REPRESENTS |
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This object represents a set of integers which is partitioned into |
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a number of disjoint subsets. It supports the two fundamental operations |
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of finding which subset a particular integer belongs to as well as |
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merging subsets. |
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!*/</font> |
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<font color='#0000FF'>public</font>: |
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<font color='#0000FF'><u>void</u></font> <b><a name='clear'></a>clear</b> <font face='Lucida Console'>(</font> |
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<font face='Lucida Console'>)</font> noexcept; |
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<font color='#009900'>/*! |
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ensures |
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- #size() == 0 |
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- returns this object to its initial value |
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!*/</font> |
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<font color='#0000FF'><u>void</u></font> <b><a name='set_size'></a>set_size</b> <font face='Lucida Console'>(</font> |
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<font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>long</u></font> new_size |
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<font face='Lucida Console'>)</font>; |
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<font color='#009900'>/*! |
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ensures |
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- #size() == new_size |
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- for all valid i: |
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- #find_set(i) == i |
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(i.e. this object contains new_size subsets, each containing exactly one element) |
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!*/</font> |
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<font color='#0000FF'><u>size_t</u></font> <b><a name='size'></a>size</b> <font face='Lucida Console'>(</font> |
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<font face='Lucida Console'>)</font> <font color='#0000FF'>const</font> noexcept; |
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<font color='#009900'>/*! |
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ensures |
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- returns the total number of integer elements represented |
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by this object. |
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!*/</font> |
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<font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>long</u></font> <b><a name='find_set'></a>find_set</b> <font face='Lucida Console'>(</font> |
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<font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>long</u></font> item |
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<font face='Lucida Console'>)</font> <font color='#0000FF'>const</font>; |
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<font color='#009900'>/*! |
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requires |
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- item < size() |
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ensures |
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- Each disjoint subset can be represented by any of its elements (since |
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the sets are all disjoint). In particular, for each subset we define |
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a special "representative element" which is used to represent it. |
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Therefore, this function returns the representative element for the |
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set which contains item. |
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- find_set(find_set(item)) == find_set(item) |
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- Note that if A and B are both elements of the same subset then we always |
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have find_set(A) == find_set(B). |
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!*/</font> |
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<font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>long</u></font> <b><a name='merge_sets'></a>merge_sets</b> <font face='Lucida Console'>(</font> |
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<font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>long</u></font> a, |
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<font color='#0000FF'><u>unsigned</u></font> <font color='#0000FF'><u>long</u></font> b |
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<font face='Lucida Console'>)</font>; |
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<font color='#009900'>/*! |
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requires |
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- a != b |
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- a < size() |
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- b < size() |
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- find_set(a) == a |
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(i.e. a is the representative element of some set) |
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- find_set(b) == b |
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(i.e. b is the representative element of some set) |
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ensures |
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- #find_set(a) == #find_set(b) |
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(i.e. merges the set's containing a and b) |
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- returns #find_set(a) |
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!*/</font> |
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<b>}</b>; |
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<font color='#009900'>// ---------------------------------------------------------------------------------------- |
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</font> |
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<b>}</b> |
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<font color='#0000FF'>#endif</font> <font color='#009900'>// DLIB_DISJOINT_SUBsETS_ABSTRACT_Hh_ |
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</font> |
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</pre></body></html> |
