写程序输出8皇后问题的所有排列，要求使用非递归的深度优先遍历。

#define COLS 10#define WAYS 100int col[COLS];int result[WAYS][COLS];bool isVaild(int level) {for (int i = 1; i < level; ++i) {if (col[i] == col[level] || abs(i - level) == abs(col[i] - col[level]))return false;}return true;}int eightQueen() {memset(col, 0, sizeof(int) * COLS);memset(result, 0, sizeof(int) * COLS * WAYS);int level = 1;col[level] = 0;int count = 0;while (level >= 1) {col[level]++;while (col[level] <= 8 && !isVaild(level)) {col[level]++;}if (col[level] <= 8) {if (level == 8) {for (int i = 1; i <= 8; ++i) {result[count][i] = col[i];}count++;} else {level++;col[level] = 0;}} else {level--;}}return count;}