POJ 1149

  1 #include <cstdio>
  2 #include <iostream>
  3 #include <cstring>
  4 #include <queue>
  5 using namespace std;
  6 #define N 105
  7 #define M 1005
  8 const int INF = 200000000;
  9 int m,n,pigs[M],st,la,max_pig;
 10 int vis[M];
 11 int pre[N] , minFlow[N]; //记录流过程用来回溯 , 到达i点的最小流量
 12 struct Edge{
 13     int c , flow;//i，j之间的容量，流量
 14 };
 15 Edge e[N][N];
 16 
 17 void build_graph()
 18 {
 19     int t , a , b;
 20     memset(vis,0,sizeof(vis));
 21     for(int i = 1 ; i<=n ; i++){
 22         scanf("%d" , &t);
 23         for(int j = 0 ; j<t ; j++){
 24             scanf("%d",&a);
 25             if(!vis[a]){
 26                 e[st][i].c += pigs[a];
 27                 vis[a] = i;
 28             }
 29             else{
 30                 e[vis[a]][i].c = INF;
 31                 vis[a] = i;
 32             }
 33         }
 34         scanf("%d" , &b); //对应客人要买的猪的数量
 35         e[i][la].c = b;
 36     }
 37 }
 38 
 39 void ford()
 40 {
 41     //初始图流量为0 
 42     for(int i=st ; i<=la ; i++)
 43             for(int j=st ; j<=la ; j++)
 44                 e[i][j].flow = 0;
 45     while(1){
 46         queue<int> q;
 47         for(int i=st ; i<=la ; i++) pre[i] = -2;
 48         q.push(st);
 49         pre[st] = -1;
 50 
 51         minFlow[st] = INF;
 52         while(!q.empty() && pre[la] == -2){
 53             int u = q.front();
 54             q.pop();
 55             for(int i = 1 ; i<=la ; i++){
 56                 int tmp = e[u][i].c - e[u][i].flow;
 57                 if(tmp > 0 && pre[i] < -1){
 58                     minFlow[i] = min(tmp , minFlow[u]);
 59                     pre[i] = u;
 60                     q.push(i);
 61                 }
 62             }
 63         }
 64 
 65 
 66         if(pre[la] < -1) break;
 67 
 68         //更新剩余网络
 69         for(int i  = pre[la] , u=la ; i!=-1 ; u=i , i=pre[i]){
 70             e[i][u].flow += minFlow[la];
 71             e[u][i].flow = -e[i][u].flow;
 72         }
 73     }
 74     for(int i = 1; i<=n ; i++)
 75     {
 76         max_pig += e[i][la].flow;
 77     }
 78 }
 79 
 80 int main()
 81 {
 82    // freopen("a.in" , "rb" , stdin);
 83     while(~scanf("%d%d",&m,&n)){
 84         for(int i=1 ; i<=m ; i++)
 85             scanf("%d",&pigs[i]);
 86 
 87         st = 0 , la = n+1;
 88         for(int i=st ; i<=la ; i++)
 89             for(int j=st ; j<=la ; j++)
 90                 e[i][j].c = 0;
 91 
 92         max_pig = 0;
 93 
 94         build_graph();
 95         ford();
 96 
 97         printf("%d" , max_pig);
 98     }
 99     return 0;
100 }