POJ 3281 Dining

#include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>
#include <cstdlib>
#include <cstring>
#include <queue>
using namespace std;

const int MAXN=5000;
const int INF=1<<30;
int N,F,D;

struct Edge{
    int to,next;
    int cap;
    Edge(int to,int next,int cap):to(to),next(next),cap(cap){};
    Edge(){};
}edges[MAXN];

int head[MAXN];
int tot;
void init(){
    memset(head,-1,sizeof(head));
    tot=0;
}

void addEdge(int u,int v,int cap){
    edges[tot].to=v;
    edges[tot].cap=cap;
    edges[tot].next=head[u];
    head[u]=tot++;
}


void initGraph(int s,int t){
    for(int i=1;i<=F;i++){
        addEdge(s,i,1);
        addEdge(i,s,0);
    }
    for(int i=1;i<=N;i++){
        addEdge(F+i,F+N+i,1);
        addEdge(F+N+i,F+i,0);
    }
    for(int i=1;i<=D;i++){
        addEdge(F+2*N+i,t,1);
        addEdge(t,F+2*N+i,0);
    }
}

int level[MAXN];
bool makelevel(int s,int t){
    //cout<<"-----------"<<endl;
    memset(level,0,sizeof(level));
    level[s]=1;
    queue<int>q;
    q.push(s);

    while(!q.empty()){
        int u=q.front();q.pop();
        if(u==t) return true;
        for(int i=head[u];i!=-1;i=edges[i].next){
            int v=edges[i].to;
            if(!level[v]&&edges[i].cap){
                level[v]=level[u]+1;
                q.push(v);
            }
        }
    }
    return false;
}

int dfs(int now,int maxf,int t){
    if(now==t) return maxf;
    int ret=0,f;

    for(int i=head[now];i!=-1;i=edges[i].next){
        int v=edges[i].to;
        if(edges[i].cap&&level[v]==level[now]+1){
            f=dfs(v,min(maxf-ret,edges[i].cap),t);
            edges[i].cap-=f;
            edges[i^1].cap+=f;
            ret+=f;
        }
        if(ret==maxf)
            return ret;
    }
    return ret;
}

int Dinic(int s,int t){
    int ans=0;
    while(makelevel(s,t))
        ans+=dfs(s,INF,t);
    return ans;
}
int  main(){
    scanf("%d%d%d",&N,&F,&D);
    init();
    initGraph(0,F+N+N+D+1);

    for(int i=1;i<=N;i++){
        int CF,CD;
        scanf("%d%d",&CF,&CD);
        for(int j=0;j<CF;j++){
            int TF;
            scanf("%d",&TF);
            addEdge(TF,F+i,1);
            addEdge(F+i,TF,0);
        }

        for(int j=0;j<CD;j++){
            int TD;
            scanf("%d",&TD);
            addEdge(F+N+i,TD+F+N+N,1);
            addEdge(TD+F+N+N,F+N+i,0);
        }
    }
    /*cout<<endl;
    for(int i=0;i<=F+N+N+D+1;i++){
        cout<<i<<"  ";
        for(int j=head[i];j!=-1;j=edges[j].next)
            cout<<edges[j].to<<"("<<edges[j].cap<<")  ";
        cout<<endl;
    }*/
    cout<<Dinic(0,F+N+N+D+1)<<endl;
    return 0;
}