hdoj 3549最大流模板

应用karp算法找最大流的模板题，对最大流一直都是不很懂，看着别人的代码打完这个感觉像是懂了点，就是一直找增广路径，直到找不到为止，求出来的就是整个的最大流

#include<iostream>
#include<cstdio>
#include<cstring>
#include<queue>
#define min(x,y) x<y?x:y
#define N 20
#define inf 0x7fffffff
using namespace std;
int tcase,n,m;
int map[N][N],flow[N],path[N];
int make_point(int s,int e)
{
    queue<int> q;
    while(!q.empty())
    q.pop();
    int t,i;
    memset(path,0,sizeof(path));
    flow[s]=inf;
    path[s]=inf;
    q.push(s);
    while(!q.empty())
    {
        t=q.front();
        q.pop();
        if(t==e)
        break;
        for(i=1;i<=n;i++)
        {
            if(map[t][i]&&!path[i]&&i!=s)
            {
                path[i]=t;
                flow[i]=min(flow[t],map[t][i]);
                q.push(i);
            }
        }
    }
    if(path[e]==0)
    return -1;
    return flow[e];
}
int karp(int s,int e)
{
    int i,j;
    int incr,step,curr,prev;
    incr=0;
    while((step=make_point(s,e))!=-1)
    {
        incr+=step;
        curr=e;
        while(curr!=s)
        {
            prev=path[curr];
            map[prev][curr]-=step;
            map[curr][prev]+=step;
            curr=prev;
        }
    }
    return incr;
}
int main()
{
    int i,j,k,x,y,c;
    int icase;
    while(scanf("%d",&tcase)!=EOF)
    {
        icase=1;
        while(tcase--)
        {
            scanf("%d%d",&n,&m);
            memset(map,0,sizeof(map));
            while(m--)
            {
                scanf("%d%d%d",&x,&y,&c);
                map[x][y]+=c;
            }
            printf("Case %d: %d\n",icase++,karp(1,n));
        }
    }
    return 0;
}