一秒内破解“最难数独”

 网上看到一则新闻，江苏69岁农民3天破解“世界最难数独”，我也写了个程序破解该数独。

原报道截图如下：

原题如下：

 

运行结果：

 

 

#include<iostream> #include<ctime>  using namespace std;int p[9][9];                  //存放九宫格数据int z[][9] = {                //分为九小宫{0,0,0,1,1,1,2,2,2},{0,0,0,1,1,1,2,2,2},{0,0,0,1,1,1,2,2,2},{3,3,3,4,4,4,5,5,5},{3,3,3,4,4,4,5,5,5},{3,3,3,4,4,4,5,5,5},{6,6,6,7,7,7,8,8,8},{6,6,6,7,7,7,8,8,8},{6,6,6,7,7,7,8,8,8},};int r[9][10];               //r[i][j]为1时，第i行数字j(1~9)已放置int c[9][10];               //c[m][n]为1时，第m列数字n(1~9)已放置int d[9][10];               //d[x][y]为1时，第x宫数字y(1~9)已放置int count;                  //解的个数void input();void output();void init();void search(int);int main(){clock_t clockBegin, clockEnd;  //用clock()来计时 毫秒 cout<<"输入:"<<endl;input();cout<<"输出:"<<endl;clockBegin = clock();          //计时开始 init();search(0);clockEnd = clock();            //计时结束 cout<<"计算用时"<< clockEnd - clockBegin<<"ms"<<endl;  return 0;}void output(){int i,j;for(i = 0; i < 9; i++){for(j = 0; j < 9; j++){cout<<p[i][j]<<' ';}cout<<endl;}count++;}void init(){int i,j,x;for(i = 0; i < 9; i++){for(j = 0; j < 9; j++){x = p[i][j];if(x == 0)continue;else{r[i][x] = 1;c[j][x] = 1;d[z[i][j]][x] = 1;}}}}void search(int cur){if(count == 1) return;else if(cur == 81)              //递归边界output();else{int i,j,k,l;i = cur / 9;                //行号j = cur % 9;                //列号if(p[i][j] != 0)search(cur + 1);else{l = z[i][j];for(k = 1; k <= 9; k++){if(r[i][k]||c[j][k]||d[l][k])   //检查行、列和宫内是否冲突continue;p[i][j] = k;r[i][k] = c[j][k] = d[l][k] = 1; //修改全局变量search(cur + 1);p[i][j] = r[i][k] = c[j][k] = d[l][k] =0;}}}}void input(){int i,j;for(i = 0; i < 9; i++)for(j = 0; j < 9;j++)cin>>p[i][j];}