POJ 1459(EK)

这题是学着小媛学姐写的..

 1 #include<cstdio>
 2 #include<cstring>
 3 #include<iostream>
 4 #include<queue>
 5 #include <climits>
 6 using namespace std;
 7 #define N 120
 8 
 9 int n, np, nc, m;
10 int cap[N][N];
11 int EK(int s, int t)
12 {
13     queue<int> q;
14     int flow[N][N];
15     int low[N];
16     int u,v,maxflow=0;
17     int pre[N];
18     memset(flow,0,sizeof(flow));
19     while(1)
20     {
21         q.push(s);
22         memset(low,0,sizeof(low));
23         low[s] = INT_MAX;
24         while(!q.empty())
25         {
26             u = q.front();
27             q.pop();
28             for(v = 0; v <= t; v ++)
29             {
30                 if(!low[v] && cap[u][v] > flow[u][v])
31                 {
32                     q.push(v);
33                     low[v] = min(low[u], cap[u][v] - flow[u][v]);
34                     pre[v] = u;
35                 }
36             }
37         }
38         if(low[t] == 0) break;
39         for(u = t; u != s; u = pre[u])
40         {
41             flow[pre[u]][u] += low[t];
42             flow[u][pre[u]] -= low[t];
43         }
44         maxflow += low[t];
45     }
46     return maxflow;
47 }
48 int main()
49 {
50     char ch;
51     int from, to, len, ans;
52     while(~scanf("%d%d%d%d",&n,&np,&nc,&m))
53     {
54         memset(cap, 0, sizeof(cap));
55         while(m--)
56         {
57             scanf(" (%d,%d)%d", &from, &to, &len);
58             cap[from][to] = len;
59         }
60         while(np--)
61         {
62             scanf(" (%d)%d",&from, &len);
63             cap[n+1][from] = len;
64         }
65         while(nc--)
66         {
67             scanf(" (%d)%d",&from, &len);
68             cap[from][n+2] = len;
69         }
70         ans = EK(n+1, n+2);
71         printf("%d\n",ans);
72     }
73     return 0;
74 }
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posted @ 2014-05-25 09:47  霖‘  阅读(115)  评论(0)  编辑  收藏  举报