poj 2965_The Pilots Brothers' refrigerator

枚举

#include<cstdio>#include<iostream>#include<cstring>using namespace std;char str[10][10];int map[10][10];void copy(){for(int i=1;i<=4;i++)for(int j=1;j<=4;j++)if(str[i-1][j-1]=='-')map[i][j]=1;elsemap[i][j]=0;}int judge(){for(int i=1;i<=4;i++)for(int j=1;j<=4;j++)if(map[i][j]==0)return 0;return 1;}void change(int k){int x=k/4;int y=k%4;for(int i=1;i<=4;i++){map[i][y+1]^=1;map[x+1][i]^=1;}map[x+1][y+1]^=1;}void print(int num,int t){printf("%d\n",num);int k=0;while(t){if(t&1){num++;int x=k/4;int y=k%4;printf("%d %d\n",x+1,y+1);}k++;t>>=1;}}int main(){while(cin>>str[0]){for(int i=1;i<4;i++)cin>>str[i];for(int i=0;i<(1<<16);i++){copy();int t=i;int num=0;int k=0;while(t){if(t&1){num++;change(k);}k++;t>>=1;}if(judge()){print(num,i);break;}}}return 0;}