poj 1273 maxflow 模版题

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连连模版把
自己对反向边的理解还不深刻！用vector比用二维数组要好！

#include<iostream>using namespace std;#include<vector>#include<cstdio>#include<algorithm>#include<cstring>const int maxn=205;const int inf=0x3f3f3f3f;typedef struct notes{    int aim,f,rev,st;}note;vector<note> G[maxn];int rev_[maxn];bool used[maxn];///int n,m;void Add_E(int u,int v,int c){    note temp;    temp.aim=v;    temp.f=c;    temp.rev=G[v].size();    G[u].push_back(temp);    temp.aim=u;    temp.f=0;///    temp.rev=G[u].size()-1;    G[v].push_back(temp);}int min_(int aa,int bb){    return aa>bb?bb:aa;}int dfs(int s,int e,int c_flow){//    printf("s=%d  e=%d\n",s,e);    if(s==e)return c_flow;    int size_=G[s].size(),fl;    used[s]=true;    for(int i=0;i<size_;i++){        note &num=G[s][i];//        printf("e=%d\n",G[s][i].aim);        if(num.f<=0)continue;        if(used[G[s][i].aim])continue;        used[num.aim]=true;        fl=dfs(G[s][i].aim,e,min_(num.f,c_flow));        if(fl>0){            num.f-=fl;            G[num.aim][num.rev].f+=fl;            return fl;        }    }    return 0;}int maxflow(int s,int e){    int ans=0,flag;//    memset(rev_,-1,sizeof(rev_));    memset(used,false,sizeof(used));    while(flag=dfs(s,e,inf)){//       printf("flag=%d\n",flag);        if(flag==inf||flag==0)break;        ans+=flag;        memset(used,false,sizeof(used));    }    return ans;}int main(){    #ifdef ONLINE_JUDGE    #else    freopen("1273.txt","r",stdin);    #endif // ONLINE_JUDGE    while(scanf("%d%d",&n,&m)!=-1){        for(int i=0;i<maxn;i++){            G[i].clear();        }        for(int i=0;i<n;i++){            int u,v,c;            scanf("%d%d%d",&u,&v,&c);            Add_E(u,v,c);        }        printf("%d\n",maxflow(1,m));    }    return 0;}

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