标签:最大流 edmondkarp acm poj
Time Limit: 1000MS | Memory Limit: 10000KB | 64bit IO Format: %I64d & %I64u |
Input
Output
Sample Input
5 4 1 2 40 1 4 20 2 4 20 2 3 30 3 4 10
Sample Output
50
Hint
Source
#include <iostream> #include <cstdio> #include <cstring> #include <queue> #include <algorithm> using namespace std; #define maxn 200 + 5 #define inf 0x7fffffff int m, n; int c[maxn][maxn],pre[maxn]; int Edmonds_Karp(int s,int t) { int minflow,maxflow = 0; while(1) { minflow = inf; memset(pre, 0 , sizeof(pre)); queue <int> q; q.push(s); while(!q.empty()) //BFS找增广路 { int x = q.front(); q.pop(); if(x == t) break; for(int i = 1;i <= n;i ++) { if(c[x][i] > 0&& pre[i] == 0) { pre[i] = x; //记录前驱 q.push(i); } } } if(pre[t] == 0) break; //终点无前驱,即没有增广路 for(int i = t; i != s;i = pre[i]) minflow = min(minflow, c[pre[i]][i]); for(int i = t; i != s;i = pre[i]) { c[pre[i]][i] -= minflow; c[i][pre[i]] += minflow; } maxflow += minflow; } return maxflow; } int main() { int from,to,cc; while(scanf("%d%d", &m, &n) != EOF) { memset(c, 0, sizeof(c)); while(m --) { scanf("%d%d%d", &from, &to, &cc); c[from][to] += cc; //可能有多条路径 } int ans = Edmonds_Karp(1,n); printf("%d\n", ans); } return 0; }
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标签:最大流 edmondkarp acm poj
原文地址:http://blog.csdn.net/mowenwen_/article/details/47778149