[洛谷 P1402] 酒店之王

#include<iostream>  
#include<cstdio>  
#include<cstring>  
#include<cstdlib>  
using namespace std;  
int n,p,q,s,t,m,ans,a[1000][1000],room[201][201],dish[201][201],dis[1000],sq[1000];  
bool BFS()  
{  
     memset(dis,0xff,sizeof(dis));  
     dis[1]=0;  
     int x,head=0,tail=1;  
     sq[1]=1;  
     while (head<tail)  
     {  
           head++;  
           x=sq[head];  
           for (int i=1;i<=t;i++)  
               if (a[x][i]>0&&dis[i]<0)  
               {  
                                     dis[i]=dis[x]+1;  
                                     tail++;  
                                     sq[tail]=i;  
               }  
     }  
     if (dis[t]>0) return true; else return false;  
}  
int find(int x,int low)  
{  
    int delta=0;  
    if (x==t) return low;  
    for (int i=1;i<=t;i++)  
        if (dis[i]==dis[x]+1&&a[x][i]>0&&(delta=find(i,min(low,a[x][i]))))  
        {  
                                         a[x][i]-=delta;  
                                         a[i][x]+=delta;  
                                         return delta;  
        }  
    return 0;  
}   
int main()  
{  
    memset(room,0,sizeof(room));  
    memset(dish,0,sizeof(dish));  
    memset(a,0,sizeof(a));  
    scanf("%d%d%d",&n,&p,&q);  
    for (int i=1;i<=n;i++)  
        for (int j=1;j<=p;j++)  
            scanf("%d",&room[i][j]);  
    for (int i=1;i<=n;i++)  
        for (int j=1;j<=q;j++)  
            scanf("%d",&dish[i][j]);  
    s=1;  
    t=n+n+p+q+2;  
    for (int i=1;i<=p;i++) a[1][i+1]=1;  
    for (int i=1;i<=n;i++) a[p+1+i][p+n+1+i]=1;  
    for (int i=1;i<=n;i++)  
        for (int j=1;j<=p;j++)  
            if (room[i][j]==1) a[j+1][p+1+i]=1;  
    for (int i=1;i<=n;i++)  
        for (int j=1;j<=q;j++)  
            if (dish[i][j]==1) a[p+n+1+i][p+n+n+1+j]=1;  
    for (int i=n+n+p+2;i<t;i++) a[i][t]=1;    
    ans=0;  
    while (BFS())    
          while(m=find(1,0x7fffffff)) ans+=m;  
    printf("%d",ans);  
    return 0;  
}  

#include<cstdio>  
#include<cstdlib>  
#include<iostream>  
#include<cstring>  
using namespace std;  
int edge[420][420],dis[420],start[420],gap[420],pre[420];  
int main()  
{  
    int a,b,p,q,c,i,j,k,n,m,h,ll,flow;  
    memset(edge,0,sizeof(edge));  
    memset(gap,0,sizeof(gap));  
    memset(start,0,sizeof(start));  
    cin >> n >> p>> q;  c=p+n; b=c+n;  
    for ( i=1; i<=n; i++)   for ( j=1; j<=p; j++)  
    {  
        cin >> a;  
        if ( a ) edge[j][i+p]++;  
    }  
    for ( i=1; i<=n; i++) edge[i+p][i+c]++;  
    for ( i=1; i<=n; i++)   for ( j=1; j<=q; j++)  
    {  
        cin >> a;  
        if ( a ) edge[i+c][b+j]++;  
    }  
    n=b+q+1;  gap[0]=n+1;  
    for ( i=1; i<=p; i++) edge[0][i]++;  
    for ( i=b+1; i<n; i++) edge[i][n]++;  
    for ( i=0; i<=n; i++)  dis[i]=0;   
    i=0; flow=0;  
    while ( dis[0]<=n )  
    {  
         ll=0;  
         for ( j=start[i]; j<=n; j++)  
         if (  edge[i][j] && dis[j]+1==dis[i] )  
         {  
             ll=1;    
             pre[j]=i;  
             i=j;  
             if ( i==n )  
             {  
                  flow++;  
                  while ( i!=0 )  
                  {  
                        h=i;  
                        i=pre[i];  
                        edge[i][h]--;  
                        edge[h][i]++;  
                  }  
             }  
             break;  
         }  
         if ( ll ) continue;  
         h=n+1;  
         for ( j=1; j<=n; j++)  
         if ( edge[i][j] && dis[j]<h )  
         {  
              h=dis[j];  
              a=j;  
         }  
         start[i]=a;  
         gap[dis[i]]--;  
         if ( !gap[dis[i]] ) break;  
         dis[i]=h+1;  
         gap[dis[i]]++;  
         if ( i!=0 ) i=pre[i];  
    }  
    cout << flow;  
    return 0;      
}