Poj 1273 drainage ditches (My EK algorithm template)

Question: Give You n sides with the target position T. Next there are each side, including the start point, end point, and capacity;

Feeling: the first code of the largest stream. This question is a deep understanding of the ek algorithm. However, this question is a pitfall, that is, the case of duplicate borders =!

Idea: EK Algorithm

AC code:

#include<stdio.h>#include<string.h>#include<algorithm>#include<queue>using namespace std;#define INF 100000000#define N 202int cap[N][N],flow[N][N];int p[N],a[N];int n,t;int Edmonds_Karp(int s){    int f=0;    queue<int >q;    while(1)    {        memset(a,0,sizeof(a));        a[s]=INF;        q.push(s);        while(!q.empty())        {            int u=q.front();            q.pop();            for(int v=1;v<=t;v++)            if(!a[v]&&cap[u][v]>flow[u][v])            {                p[v]=u;                q.push(v);                a[v]=min(a[u],cap[u][v]-flow[u][v]);            }        }        if(a[t]==0)break;        for(int u=t;u!=s;u=p[u])        {            flow[p[u]][u]+=a[t];            flow[u][p[u]]-=a[t];        }        f+=a[t];    }    return  f;}int main(){    int u,v,w,i,j;    while(scanf("%d %d",&n,&t)!=EOF)    {        memset(cap,0,sizeof(cap));        memset(flow,0,sizeof(flow));        for(i=0;i<n;i++)        {            scanf("%d %d %d",&u,&v,&w);            cap[u][v]+=w;        }        printf("%d\n",Edmonds_Karp(1));    }    return 0;}