KnightsTour

I/P:

5

2

0

O/P:

25 2 13 8 23 

12 7 24 3 14 

1 18 15 22 9 

6 11 20 17 4 

19 16 5 10 21 

19 2 13 8 21 

12 7 20 3 14 

1 18 15 22 9 

6 11 24 17 4 

25 16 5 10 23 ...

package pep.Day12;

import java.util.Scanner;

public class KnightsTour {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int n = sc.nextInt();
        int r = sc.nextInt();
        int c = sc.nextInt();

        int[][] chess = new int[n][n];

        printKnightsTour(chess, r, c, 1);
    }

    public static void printKnightsTour(int[][] chess, int r, int c, int upcomingMove) {
        if (r < 0 || c < 0 || r >= chess.length || c >= chess.length || chess[r][c] != 0)
            return;
        else if (upcomingMove == chess.length * chess.length) {
            // update chess.length * chess.length's move
            chess[r][c] = upcomingMove;
            displayBoard(chess);
            // again update to 0 for the further process
            chess[r][c] = 0;
            return;
        }


        int[][] dirns = {{-2, 1}, {-1, 2}, {1, 2}, {2, 1},
                {2, -1}, {1, -2}, {-1, -2}, {-2, -1}};

        chess[r][c] = upcomingMove;
        for (int[] dir : dirns) {
            printKnightsTour(chess, r + dir[0], c + dir[1], upcomingMove + 1);
        }
        // this is used in fallback when no block present to move further
        chess[r][c] = 0;
    }

    public static void displayBoard(int[][] chess) {
        for (int i = 0; i < chess.length; i++) {
            for (int j = 0; j < chess[0].length; j++) {
                System.out.print(chess[i][j] + " ");
            }
            System.out.println();
        }

        System.out.println();
    }
}