hdu 1532 最大流

#include <cstdio>#include <iostream>#include <algorithm>#include <queue>#include <cmath>#include <cstring>#include <stack>#include <set>#include <map>#include <vector>using namespace std;#define INF 0x4fffffff#define LL long long#define MAX(a,b) ((a)>(b))?(a):(b)#define MIN(a,b) ((a)<(b))?(a):(b)int n,m;LL c[205][205];LL f[205][205];LL a[205];LL pre[205];void max_flow(){memset(f,0,sizeof(f));LL ans  = 0;while(1){memset(a,0,sizeof(a));queue<int> que;que.push(1);a[1] = INF;while(!que.empty()){int u = que.front();que.pop();for(int i = 1;i <= m;i++){if(!a[i] && c[u][i] > f[u][i]){pre[i] = u;a[i] = min(a[u],c[u][i] - f[u][i]);que.push(i);}}}if(a[m] == 0) break;for(int u = m; u!=1;u = pre[u]){f[pre[u]][u] += a[m];f[u][pre[u]] -= a[m];}ans += a[m];}cout << ans << endl; }int main(){while(scanf("%d%d",&n,&m)!=EOF){memset(c,0,sizeof(c));for(int i = 0;i < n;i++){int x,y,w;scanf("%d%d%d",&x,&y,&w);c[x][y] += w;}max_flow();}return 0;}