hdu3549-网络流水题

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和hdu1532没有什么区别，直接上代码：

#include<cstdio>#include<cstring>#include<queue>#include<iostream>using namespace std;const int INF=0x3f3f3f3f;const int Maxn=20;int pre[Maxn];int capacity[Maxn][Maxn];int flow[Maxn];queue<int> que;int n,m;int Min(int a,int b){    return a<b?a:b;}int BFS(int src ,int des){    while(!que.empty())        que.pop();    memset(pre,-1,sizeof(pre));    que.push(src);    pre[src]=0;    flow[src]=INF;    while(!que.empty())    {        int index=que.front();        que.pop();        if(index==des)            break;        for(int i=1;i<=n;i++)        {            if(i!=src&&capacity[index][i]>0&&pre[i]==-1)            {                flow[i]=Min(flow[index],capacity[index][i]);                pre[i]=index;                que.push(i);            }        }    }    if(pre[des]==-1)        return -1;    else        return flow[des];}int maxFlow(int src,int des){    int increasement=0;    int sumFlow=0;    while((increasement=BFS(src,des))!=-1)    {        int k=des;        while(k!=src)        {            int last=pre[k];            capacity[last][k]-=increasement;            capacity[k][last]+=increasement;            k=last;        }        sumFlow+=increasement;    }    return sumFlow;}int main(){    //freopen("in.txt","r",stdin);    int T;    scanf("%d",&T);    int cas=1;    while(T--)    {        scanf("%d%d",&n,&m);        memset(capacity,0,sizeof(capacity));        memset(flow,0,sizeof(flow));        int start,end,ci;        for(int i=1;i<=m;i++)        {            scanf("%d%d%d",&start,&end,&ci);            capacity[start][end]+=ci;        }        printf("Case %d: %d\n",cas,maxFlow(1,n));        cas++;    }}

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