forked from bartvdbraak/blender
86 lines
912 B
C++
86 lines
912 B
C++
#include "UnionFind.h"
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#include <assert.h>
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int UnionFind::find(int x)
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{
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assert(x < m_N);
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assert(x >= 0);
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while (x != m_id[x])
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{
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x = m_id[x];
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assert(x < m_N);
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assert(x >= 0);
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}
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return x;
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}
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UnionFind::~UnionFind()
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{
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Free();
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}
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UnionFind::UnionFind()
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:m_id(0),
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m_sz(0),
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m_N(0)
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{
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}
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void UnionFind::Allocate(int N)
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{
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if (m_N < N)
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{
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Free();
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m_N = N;
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m_id = new int[N];
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m_sz = new int[N];
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}
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}
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void UnionFind::Free()
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{
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if (m_N)
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{
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m_N=0;
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delete m_id;
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delete m_sz;
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}
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}
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void UnionFind::reset(int N)
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{
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Allocate(N);
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for (int i = 0; i < m_N; i++)
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{
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m_id[i] = i; m_sz[i] = 1;
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}
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}
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int UnionFind ::find(int p, int q)
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{
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return (find(p) == find(q));
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}
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void UnionFind ::unite(int p, int q)
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{
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int i = find(p), j = find(q);
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if (i == j)
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return;
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if (m_sz[i] < m_sz[j])
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{
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m_id[i] = j; m_sz[j] += m_sz[i];
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}
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else
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{
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m_id[j] = i; m_sz[i] += m_sz[j];
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}
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}
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