POJ 1459最大流模板

//POJ1459
//Memory：1060K
//Time： 797MS
#include<iostream>
#include<cstdio>
#include<cstring>
#include<vector>
#include<queue>
using namespace std;

const int MAXN = 110;
const int INF = 1e9+9;

struct Node
{
int to; ///终点
int cap; ///容量
int rev; ///反向边
Node(int _to,int _cap,int _rev):to(_to),cap(_cap),rev(_rev){}

};

vector <Node> edge[MAXN];

void add_node(int from,int to,int cap)
{
// v[from].push_back((Node){to,cap,v[to].size()});
edge[from].push_back(Node(to,cap,edge[to].size()));
///反向边就是最后加入的那个
edge[to].push_back(Node(from,0,edge[from].size()-1));
///因为上一语size句刚刚+一，故要-1
}

int level[MAXN];  //层数

bool BFS(int s, int t)
{
queue<int>q;
memset(level, -1, sizeof(level));
level[s] = 0;
q.push(s);

while(!q.empty())
{//cout<<"1"<<endl;
int pre = q.front(); q.pop();

for(int i=0; i<edge[pre].size(); ++i)////////////////////
{
Node &tmp1 = edge[pre][i];

if(tmp1.cap > 0 && level[tmp1.to] == -1)
{
level[tmp1.to] = level[pre] + 1;
q.push(tmp1.to);
}

}

}
return level[t] != -1;
}

int DFS(int u, int t, int flow)
{//cout<<"2"<<endl;
if(u == t) return flow;

int tf = 0; ///
for(int i=0; i<edge[u].size(); ++i)////////////////////
{
Node &tmp2 = edge[u][i];
if(tmp2.cap>0 && flow>tf &&level[tmp2.to]==level[u]+1)
{
int f = DFS(tmp2.to,t,min(flow-tf, tmp2.cap));
if(f>0)
{
tmp2.cap -= f;
edge[tmp2.to][tmp2.rev].cap += f;
tf += f;
}

}
}
if(tf==0) level[u] = -1;
return tf;
}

int DINIC(int s, int t)
{
int ans = 0;
while(BFS(s,t))
{
int  tp;
while(tp = DFS(s,t,INF))
ans += tp;
}
return ans;
}

int main()
{

int n,np,nc,m;
// while(scanf("%d%d%d%d",&n,&np,&nc,&m)!=EOF)
while(cin>>n>>np>>nc>>m)
{
for(int i=0;i<MAXN; ++i)
edge[i].clear();

char t1,t2,t3;
int u, v, cap;
for(int i=1; i<=m; ++i)
{
//scanf("%c%d%c%d%c%d",&t1,&u,&t2,&v,&t3,&cap);
cin>>t1>>u>>t2>>v>>t3>>cap;
if(u==v) continue;
add_node(u,v,cap);
}

int s = n+1;
int t = n+2;
for(int i=1; i<=np; ++i)
{
//scanf("%c%d%c%d",&t1,&v,&t2,&cap);
cin>>t1>>v>>t2>>cap;
add_node(s,v,cap);
}

for(int i=1; i<=nc; ++i)
{
//scanf("(%d)%d",u,cap);
//scanf("%c%d%c%d",&t1,&u,&t2,&cap);
cin>>t1>>u>>t2>>cap;
add_node(u,t,cap);
}

//printf("%d\n", DINIC(s, t));
cout<<DINIC(s,t)<<endl;
}
return 0;
}