package queens;

import java.util.Scanner;

public class Queens {

    static int[] queens;
    int row = 0;

    public Queens() {
        Scanner scan = new Scanner(System.in);
        System.out.println("Please Enter A Number");
        //int x = scan.nextInt();
        queens = new int[4];

    }

     boolean safe(int col) {
        int current = queens[col];
        for (int i = 1; i <= row; i++) {
            int pre = queens[col - i];
            if (pre == current
                    || pre == current - i
                    || pre == current + i) {
                return false;
            }
        }
        return true;
    }

    public void placeQueens(int row) {
        for (int col = 0; col < queens.length; col++) {
            if (safe(col)) {
                queens[row] = col;
                if (row == queens.length - 1) {
                    printOut();
                } else {
                    row++;
                    placeQueens(row);
                }

            }
        }
    }

    public void printOut() {

        for (int i = 0; i < queens.length; i++) {

            for (int j = 0; j < queens.length; j++) {
                if (queens[i] == j) {
                    System.out.print("Q");
                } else {
                    System.out.print("*");
                }
            }
            System.out.println("");
        }
        System.out.println("");
    }

    public static void main(String[] args) {
        Queens q = new Queens();
        q.placeQueens(0);
        //q.printOut();
    }

}