poj2965

这题和1753差不多，多了一个数位压缩状态，记录翻了的点

#include<iostream>  
#include <string>   
#include<vector>  
#include<algorithm>  
#include<set>  
#include<cmath>  
using namespace std;  
#define lch(i) ((i)<<1)  
#define rch(i) ((i)<<1|1)  
#define sqr(i) ((i)*(i))  
#define pii pair<int,int>  
#define mp make_pair  
#define FOR(i,b,e) for(int i=b;i<=e;i++)  
#define ms(a)   memset(a,0,sizeof(a))  
const int maxnum = 10005;  
  
  
int mat[4][4];  
bool vis[4][4];  
  
  
void flip(int x,int y){  
    mat[x][y]=1-mat[x][y];  
    FOR(i,0,3) mat[i][y]=1-mat[i][y];
	FOR(i,0,3) mat[x][i]=1-mat[x][i];
    /*printf("\n"); 
    FOR(i,0,3){ 
        FOR(j,0,3){ 
            printf("%d",mat[i][j]); 
        } 
        printf("\n"); 
    }*/  
  
}  
  
bool check(){  
    int sum=0;  
    FOR(i,0,3){  
        FOR(j,0,3){  
            sum+=mat[i][j];  
        }  
    }  
    if (sum==16)  
    {  
        return true;  
    }  
    return false;  
}  
  
  
int mintime=100, mindp=0;
void enumM(int n,int times ,int dp){  
    if(n==16)return;  
    enumM(n+1,times,dp);  
  
  
    flip(n/4,n%4);  
    if(check()){  
        mintime=min(mintime,times);  
		mindp = dp|(1<<n);
    }  
    enumM(n+1,times+1,dp|(1<<n));  
    flip(n/4,n%4);  
}  
  
int main()  
{  
    char ch;  
    FOR(i,0,3){  
        FOR(j,0,3){  
            scanf("%c",&ch);  
            if(ch=='+')mat[i][j]=0;  
            else        mat[i][j]=1;  
        }scanf("%c",&ch);  
    }  
    ms(vis);  
    if(check()) printf("0\n");  
    else{  
        enumM(0,1,0);  
        if(mintime>16)printf("Impossible\n");  
        else printf("%d\n",mintime);  
		
		int tmp,val;
		while(mindp){
			val=0;
			tmp = mindp & (-mindp);
			mindp -=tmp;
			while(tmp){
				val++;
				tmp =tmp>>1;
			};
			val--;
			printf("%d %d\n",val/4+1,val%4+1);
		}


    }  
}