hdu 1532 Drainage Ditches

#include <cstring>
#include <cstdio>
#include <queue>

using namespace std;
struct node
{
    int next,to,flow;
}edge[200*200+1];
int deep[200*200],head[200*200+1],ans,s,t,n,m,i,j,cnt=1;
void add(int u,int v,int l)
{
    cnt++;
    node * now=&edge[cnt];
    now->next=head[u];
    now->to=v;
    now->flow=l;
    head[u]=cnt;
}
bool bfs(int s,int t)
{
    memset(deep,-1,sizeof(deep));
    deep[s]=0;
    queue<int>q;
    q.push(s);
    while(!q.empty())
    {
        int tp=q.front();
        q.pop();
        for(i=head[tp];i;i=edge[i].next)
        {
            if(deep[edge[i].to]==-1&&edge[i].flow>0)
            {
                deep[edge[i].to]=deep[tp]+1;
                if(edge[i].to==t) return 1;
                else q.push(edge[i].to); 
            }
        }
    }
    return 0;
}
int dfs(int now,int t,int came_flow)
{
    if(now==t||came_flow==0) return came_flow;
    int rest=0,f;
    for(int i=head[now];i;i=edge[i].next)
    {
        int v=edge[i].to;
        if(deep[v]==deep[now]+1&&edge[i].flow>0)
        {
            f=dfs(v,t,min(came_flow,edge[i].flow));
            if(f)
            {
                rest+=f;
                came_flow-=f;
                edge[i].flow-=f;
                edge[i^1].flow+=f;
            }
            if(came_flow==0) return rest;
        }
    }
    return rest;
}
void Dinic(int s,int t)
{
    while(bfs(s,t))
    ans+=dfs(s,t,1e9);
}
int main()
{
    while(scanf("%d%d",&n,&m)!=EOF)//一定用这个读入，因为这WA了好多次
    {
        int a,b,c;
        s=1,t=m;ans=0;
        memset(head,0,sizeof(head));
        cnt=1;
        while(n--)
        {
            scanf("%d%d%d",&a,&b,&c);
            add(a,b,c);
            add(b,a,0);
        }
        Dinic(s,t);
        printf("%d\n",ans);
    }
    return 0;
}