Food HDU - 4292

关键在于建图，食物放左边，饮料放右边，人员放中间。
需要注意的是，人员要拆点，保证一人只能吃一份。
以后都不用dinic了，都用ISAP

#include<iostream>
#include<algorithm>
using namespace std;
const int max_n = 900;
const int max_m = max_n*max_n;
const int inf=0x3f3f3f3f;
struct edge {
    int to,cap,next;
}E[max_m<<2];
int n;
int head[max_n],cnt=1,gap[max_n],last[max_n],d[max_n],que[max_n],ql,qr;
void add(int u,int to,int cap) {
    E[++cnt].to=to;E[cnt].cap=cap;
    E[cnt].next=head[u];head[u]=cnt;
    E[++cnt].to=u;E[cnt].cap=0;
    E[cnt].next=head[to];head[to]=cnt;
}int aug(int x,int s,int t,int mi) {
    if (x==t) return mi;
    int flow=0;
    for (int &i=last[x],v=E[i].to;i;i=E[i].next,v=E[i].to) if (d[x]==d[v]+1) {
        int tmp=aug(v,s,t,min(mi,E[i].cap));
        flow+=tmp,mi-=tmp,E[i].cap-=tmp,E[i^1].cap+=tmp;
        if (!mi) return flow;
    }
    if (!(--gap[d[x]])) d[s]=n+1;
    ++gap[++d[x]],last[x]=head[x];
    return flow;
}
int maxflow(int s,int t) {
    fill(gap,gap+n+10,0);fill(d,d+n+10,0);
    ++gap[d[t]=1];
    for (int i=1;i<=n;++i) last[i]=head[i];
    que[ql=qr=1]=t;
    while (ql<=qr) {
        int x=que[ql++];
        for (int i=head[x],v=E[i].to;i;i=E[i].next,v=E[i].to) if (!d[v]) ++gap[d[v]=d[x]+1],que[++qr]=v;
    }

    int ret=aug(s,s,t,inf);
    while (d[s]<=n)    ret+=aug(s,s,t,inf);
    return ret;
}
int N,F,D;
int main(){
    while(~scanf("%d %d %d",&N,&F,&D)){
    int s = N+F+D+N+1;int t = s+1;
    n = t;
    fill(head,head+n+5,0);cnt=1;
    for (int i=1;i<=F;++i){
        int cap;scanf("%d",&cap);
        add(s,i,cap);
    }
    for (int i=1;i<=D;++i){
        int cap;scanf("%d",&cap);
        add(i+F+N,t,cap);
    }
    for (int i=1;i<=N;++i)add(i+F,i+F+D+N,1);
    for (int i=1;i<=N;++i){
        char c[400];
        scanf("%s",c+1);
        for (int j=1;j<=F;++j)
            if (c[j]=='Y')add(j,i+F,1);
    }
    for (int i=1;i<=N;++i){
        char c[400];
        scanf("%s",c+1);
        for (int j=1;j<=D;++j)
            if (c[j]=='Y')add(i+F+D+N,j+N+F,1);
    }
    printf("%d\n",maxflow(s,t));
    }
}