回溯法, 八皇后

//打开label1处的打印可以看到八皇后的所有解//阅读程序可通过关闭label1打开label2单步调试查看arr的值来理解回溯法#include <stdio.h>#include <math.h>int arr[9] = {0};//例如arr[1] = 4, arr[2] = 1;表示棋盘第一行第4列以及//第2行第1列放上棋子//arr[0]不使用void Print(){static int count = 1;printf("-----%d-----/n", count++);int print_arr[9][9] = {0};for (int i=1; i<=8; ++i)print_arr[i][arr[i]] = 1;for (int j=1; j<=8; ++j){for (int k=1; k<=8; ++k){printf("%d", print_arr[j][k]);}printf("/n");}}bool Check(int m){for (int i=1; i<m; ++i){//检查m行以上的行有没有与m行同列或者在斜线上if (arr[m] == arr[i] || (m-i) == abs(arr[m]-arr[i]))return false;}return true;}void Queen(int m){if (m > 8){Print(); //label1return;}for (int n=1; n<=8; ++n){arr[m] = n;if (Check(m)){//printf("(%d, %d)", m, arr[m]);//label2Queen(m+1);}}return;}int main(){Queen(1);return 0;}