#include <stdio.h>
#include <stdbool.h>
#define N 8
void printSolution(int board[N][N]) {
for (int i = 0; i < N; i++) {
for (int j = 0; j < N; j++) {
printf("%c ", board[i][j] ? 'Q' : '.');
}
printf("\n");
}
printf("\n");
}
bool isSafe(int board[N][N], int row, int col) {
for (int i = 0; i < row; i++) {
if (board[i][col]) {
return false;
}
}
for (int i = row, j = col; i >= 0 && j >= 0; i--, j--) {
if (board[i][j]) {
return false;
}
}
for (int i = row, j = col; i >= 0 && j < N; i--, j++) {
if (board[i][j]) {
return false;
}
}
return true;
}
void solveNQueens(int board[N][N], int row) {
if (row == N) {
printSolution(board);
return;
}
for (int col = 0; col < N; col++) {
if (isSafe(board, row, col)) {
board[row][col] = 1;
solveNQueens(board, row + 1);
board[row][col] = 0;
}
}
}
int main() {
int board[N][N] = {0};
solveNQueens(board, 0);
return 0;
}