全局最小割模板 poj2914

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http://poj.org/problem?id=2914
参考资料：http://www.hankcs.com/program/algorithm/poj-2914-minimum-cut.html
就是单纯的全局最小割

#include <iostream>#include <cstdio>#include <cstring>#include <algorithm>#include <queue>#include <vector>using namespace std;#define M 1009const int INF = 0x3f3f3f3f;int G[M][M];int w[M],v[M];bool vis[M];int n,m;int sw(int n){    int min_cut = INF;    for(int i = 0;i < n;i++) v[i] = i;    while(n > 1)    {        int pre = 0;        memset(vis,false,sizeof(vis));        memset(w,0,sizeof(w));        for(int i = 1;i < n;i++)        {            int k = -1;            for(int j = 1;j < n;j++)            {                if(vis[v[j]]) continue;                w[v[j]] += G[v[pre]][v[j]];                if(k == -1 || w[v[k]] < w[v[j]])                {                    k = j;                }            }            vis[v[k]] = true;            if(i == n-1)            {                int s = v[pre],t = v[k];                min_cut = min(min_cut,w[t]);                for(int j = 0;j < n;j++)                {                    G[s][v[j]] += G[t][v[j]];                    G[v[j]][s] += G[v[j]][t];                }                v[k] = v[--n];            }            pre = k;        }    }    return min_cut;}int main(){    while(scanf("%d %d",&n,&m) == 2)    {        memset(G,0,sizeof(G));        for(int i = 0;i < m;i++)        {            int u,v,ww;            scanf("%d %d %d",&u,&v,&ww);            G[u][v] += ww;            G[v][u] += ww;        }        int min_cut = sw(n);        printf("%d\n",min_cut);    }    return 0;}

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