41 lines
No EOL
743 B
C++
41 lines
No EOL
743 B
C++
#pragma once
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#include <vector>
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namespace cgv {
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namespace data {
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struct union_find : public std::vector<unsigned int>
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{
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/// construct with given number of elements
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union_find(unsigned int n) { init(n); }
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/// init such that each element is a representative
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void init(unsigned int n) {
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resize(n);
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for (unsigned int i=0; i<n; ++i)
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at(i) = i;
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}
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/// find representative with path compression
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unsigned int find(unsigned int i)
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{
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// find representative j
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unsigned int j = i;
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while (at(j) != j)
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j = at(j);
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// compress path
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while (i != j) {
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unsigned int tmp = at(i);
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at(i) = j;
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i = tmp;
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}
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return j;
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}
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/// union of two groups
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void unify(unsigned int i, unsigned int j)
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{
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at(find(i)) = j;
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}
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};
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}
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} |