[kuangbin带你飞]专题一 简单搜索

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
int x, y;
bool g[20][20];
bool k[20][20]; 
bool ans[20][20];
bool flag;
int d[5][2] = {{0,-1},{0,1},{-1,0},{1,0},{0,0}};
bool judge(int cur)
{
    for(int i = 1; i <= x; i++)
        for(int j = 1; j <= y; j++)
        {
            k[i][j] = g[i][j];
        }
    for(int j = 0; j < y; j++)
    {
        k[0][j+1] = (cur>>j)%2;
    }

    for(int i = 1; i <= x; i++)
        for(int j = 1; j <= y; j++)
        {
            if(k[i-1][j] == false)    continue;
            ans[i][j] = true;
            for(int z = 0; z <= 4; z++)
            {
                k[i+d[z][0]][j+d[z][1]] = !k[i+d[z][0]][j+d[z][1]];
            }
        }
        
    for(int j = 1; j <= y; j++)
    {
        if(k[x][j])    return false;
    }
    return true;
}
int main()
{
//    freopen("in.in","r",stdin);
    while(scanf("%d%d",&x,&y)!=EOF)
    {
        flag = false;
        for(int i = 1; i <= x; i++)
            for(int j = 1; j <= y; j++)
            {
                scanf("%d",&g[i][j]);
            }
        for(int i = 0; i < (1<<y); i++)
        {
            memset(ans,0,sizeof(ans)); 
            
            if(judge(i))
            {
                flag = true;
                break;
            }    
    
        }
        if(flag)
        {
            for(int i = 1; i <= x; i++)
            {
                cout<<ans[i][1];
                for(int j = 2; j <= y; j++)
                {
                    cout<<" "<<ans[i][j];
                }        
                printf("
");
            }        
        }
        else    printf("IMPOSSIBLE
");        
    }


    return 0;
}