poj 1222

分类里说的是高斯消元，但我没看出来，就先搜给搜出来了，一会看看别人怎么消的。

//============================================================================
// Name        : 1222.cpp
// Author      : 
// Version     :
// Copyright   : Your copyright notice
// Description : Hello World in C++, Ansi-style
//============================================================================

#include <iostream>
#include <cstdio>
#include <cstring>
using namespace std;

int in[10][10], b[10][10];
int N, tag;


void press(int x, int y){
	in[x][y] = in[x][y] == 1?0:1;
//	printf("%d %d %d\n", x, y, in[x][y]);
	if(x > 1){
		in[x-1][y] = in[x-1][y] == 1?0:1;
	}
	if(x < 5){
		in[x+1][y] = in[x+1][y] == 1?0:1;
	}
	if(y > 1){
		in[x][y-1] = in[x][y-1] == 1?0:1;
	}
	if(y < 6){
		in[x][y+1] = in[x][y+1] == 1?0:1;
	}
}

void dfs(int m){
	if(tag == 1) return;
	if(m == 7){
		int flag = 1;
		for(int i = 2;i <= 5;i++){
			for(int j = 1;j <= 6;j++){
				if(in[i-1][j] == 1){
					press(i, j);
					b[i][j] = 1;
				}
				else{
					b[i][j] = 0;
				}
			}
		}
		for(int i = 1;i <= 6;i++){
			if(in[5][i] != 0){
				flag = 0;
			}
		}
		if(flag == 0){
			for(int i = 2;i <= 5;i++){
				for(int j = 1;j <= 6;j++){
					if(b[i][j] == 1){
						press(i, j);
					}
				}
			}
			return;
		}
//		for(int i = 1;i <= 5;i++){
//			for(int j = 1;j <= 6;j++){
//				printf("%d ", in[i][j]);
//			}
//			printf("\n");
//		}printf("\n");
		tag = 1;
		for(int i = 1;i <= 5;i++){
			for(int j = 1;j <= 6;j++){
				if(j == 1){
					printf("%d", b[i][j]);
				}
				else{
					printf(" %d", b[i][j]);
				}
			}
			printf("\n");
		}
	}
	else{
		b[1][m] = 0;
		dfs(m+1);
		press(1, m);
		b[1][m] = 1;
		dfs(m+1);
		press(1, m);
	}
}



int main() {
	scanf("%d", &N);
	for(int T = 1;T <= N;T++){
		for(int i = 1;i <= 5;i++){
			for(int j = 1;j <= 6;j++){
				scanf("%d", &in[i][j]);
			}
		}
		tag = 0;
		printf("PUZZLE #%d\n",T);
		dfs(1);
//		press(1, 6);
//		in[1][1] = in[1][1] == 1?0:1;
//		for(int i = 1;i <= 5;i++){
//			for(int j = 1;j <= 6;j++){
//				printf("%d ", in[i][j]);
//			}
//			printf("\n");
//		}
	}
	return 0;
}