#include <iostream>
using namespace std;

int data[17][301];
int row;
int ans[301];
int m,n;

int DFS(int row)
{
    int f=0;
    int fans[301];
    int sans[301];
    if(row>m)
        return 0;
    for(int i=1;i<=n;i++)
    {
        sans[i]=ans[i];
        ans[i]=ans[i]+data[row][i];

        if(ans[i]==0)
            f=1;            
        if(ans[i]>1)
            return 0;  
    }
    if(!f)
        return 1;
    for(int i=row+1;i<=m;i++)
    {
        for(int j=1;j<=n;j++)
            fans[j]=ans[j];
        if(DFS(i))
            return 1;
        else
        {
            for(int j=1;j<=n;j++)
                ans[j]=fans[j];
        }
    }
    for(int i=1;i<=n;i++)
        ans[i]=sans[i];
    return DFS(row+1);
}
    
    
    
    
int main()
{

    while( cin>>m>>n )
    {
        for(int i=1;i<=m;i++)
            for(int j=1;j<=n;j++)
                cin>>data[i][j];
        memset(ans,0,sizeof(ans));
        if(DFS(1))
            cout<<"Yes, I found it"<<endl;
        else
            cout<<"It is impossible"<<endl;
    }
}

• Re:WA 到我死，能找到的测试数据全过，大牛们看看这到底是为什么？ (23) Acm06001_200 2009-08-25 11:00:32