BZOJ1433: [ZJOI2009]假期的宿舍

1433: [ZJOI2009]假期的宿舍

Time Limit: 10 Sec  Memory Limit: 162 MB
Submit: 1141  Solved: 491
[Submit][Status]

Description

Input

Output

Sample Input

1
3
1 1 0
0 1 0
0 1 1
1 0 0
1 0 0

Sample Output

ˆ ˆ

HINT

对于30% 的数据满足1 ≤ n ≤ 12。
对于100% 的数据满足1 ≤ n ≤ 50,1 ≤ T ≤ 20。

题解：

左边是人，右边是床，dinic即可

注意逻辑关系即可

代码：

#include<cstdio>
#include<cstdlib>
#include<cmath>
#include<cstring>
#include<algorithm>
#include<iostream>
#include<vector>
#include<map>
#include<set>
#include<queue>
#define inf 1000000000
#define maxn 100+100
#define maxm 2500+100
#define eps 1e-10
#define ll long long
using namespace std;
inline int read()
{
    int x=0,f=1;char ch=getchar();
    while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
    while(ch>='0'&&ch<='9'){x=10*x+ch-'0';ch=getchar();}
    return x*f;
}
struct edge{int go,next,v;}e[2*maxm];
int n,m,s,t,tot=1,maxflow,head[maxn],q[maxn],h[maxn],cur[maxn];
bool a[maxn],b[maxn];
void ins(int x,int y,int z){e[++tot].go=y;e[tot].v=z;e[tot].next=head[x];head[x]=tot;}
void insert(int x,int y,int z){ins(x,y,z);ins(y,x,0);}
bool bfs()
{
    for(int i=s;i<=t;i++)h[i]=-1;
    int l=0,r=1;q[1]=s;h[s]=0;
    while(l<r) 
    {
        int x=q[++l];
        for(int i=head[x];i;i=e[i].next)
         if(e[i].v&&h[e[i].go]==-1)
         {
             h[e[i].go]=h[x]+1;q[++r]=e[i].go;
         }
    }
    return h[t]!=-1;
}
int dfs(int x,int f)
{
    if(x==t) return f;
    int tmp,used=0,i;
    for(int i=head[x];i;i=e[i].next)
     if(e[i].v&&h[e[i].go]==h[x]+1) 
    {
        tmp=dfs(e[i].go,min(e[i].v,f-used));
        e[i].v-=tmp;if(e[i].v)cur[x]=i; 
        e[i^1].v+=tmp;used+=tmp;
        if(used==f)return f;         
    }
    if(!used) h[x]=-1;
    return used; 
}
void dinic()
{
    maxflow=0;
    while(bfs())
    {
        for (int i=s;i<=t;i++)cur[i]=head[i];maxflow+=dfs(s,inf); 
    } 
}
int main()
{
    freopen("input.txt","r",stdin);
    freopen("output.txt","w",stdout);
    int cs=read();
    while(cs--)
    {    
     memset(a,0,sizeof(a));
     memset(b,0,sizeof(b));
     memset(head,0,sizeof(head));tot=1;
     n=read();int x;
     for(int i=1;i<=n;i++)a[i]=read();
     for(int i=1;i<=n;i++){x=read();if(x&&a[i])b[i]=1;}
     //for(int i=1;i<=n;i++)cout<<i<<' '<<a[i]<<' '<<b[i]<<endl;
     s=0;t=2*n+1;
     for(int i=1;i<=n;i++)
     {
         if(!b[i]&&a[i])insert(i,i+n,1);
        for(int j=1;j<=n;j++){x=read();if(!b[i]&&x&&a[j])insert(i,j+n,1);}
     }
     int ans=0;
     for(int i=1;i<=n;i++)if(!b[i])insert(s,i,1),ans++;
     for(int i=1;i<=n;i++)if(a[i])insert(i+n,t,1);
     dinic();
     //cout<<ans<<' '<<maxflow<<endl;
     if(maxflow==ans)printf("%c%c%c\n",94,95,94);else printf("%c%c%c\n",84,95,84);
    }
    return 0;
}