hdu 3549 Flow Problem 【最大流】

其实还是不是很懂dinic-----

抄了一个模板---

http://www.cnblogs.com/naturepengchen/articles/4403408.html

先放在这里～～～

 #include<cstdio>
 #include<cstring>
 #include<iostream>
 #include<algorithm>
 #include<queue>
 using namespace std;

 const int maxn = ;
 const int INF = ( << ) - ;

 struct Edge{
     int v,next,c;
 }e[maxn];

 int st,ed,lev[maxn],first[maxn],now[maxn],ecnt;
 int n,m;

 void init(int a,int b){
     st = a; ed = b;
     memset(first,-,sizeof(first));
     ecnt = ;
 }

 void addedges(int u,int v,int c){
     e[ecnt].next = first[u];
     e[ecnt].v = v;
     e[ecnt].c = c;
     first[u] = ecnt++;

     e[ecnt].next = first[v];
     e[ecnt].v = u;
     e[ecnt].c = ;
     first[v] = ecnt++;
 }

 bool bfs(){
     queue<int> q;
     while(!q.empty()) q.pop();
     q.push(st);
     memset(lev,-,sizeof(lev));
     lev[st] = ;
     while(!q.empty()){
         int x = q.front();q.pop();
         for(int i = first[x];~i;i = e[i].next){
             int v = e[i].v;
             if(lev[v] <  && e[i].c > ){
                 lev[v] = lev[x] + ;
                 q.push(v);
             }
         }
     }
     return lev[ed] != -;
 }

 int dfs(int p,int minf){
     if(p == ed || minf == ) return minf;
     for(int &i = now[p];~i;i = e[i].next){
         int v = e[i].v;
         if(lev[v] == lev[p] +  && e[i].c > ){
             int d = dfs(v,min(e[i].c,minf));
             if(d > ){
                 e[i].c -= d;
                 e[i^].c += d;
                 return d;
             }
         }
     }
     return ;
 }

 int dinic(){
     int max_flow = ,p1;
     while(bfs()){
         memcpy(now,first,sizeof(first));
         while((p1 = dfs(st,INF)) > )
         max_flow += p1;
     }
     return max_flow;
 }

 int main(){
     int T;
     int kase = ;
     scanf("%d",&T);
     while(T--){
         scanf("%d %d",&n,&m);
         init(,n);
         for(int i = ;i < m;i++){
             int a,b,c;
             scanf("%d %d %d",&a,&b,&c);
             addedges(a,b,c);
         }
         printf("Case %d: %d\n",++kase,dinic());
     }
     return ;
 }