Sudoku Solver

import java.util.*;
public class SudokuSolver {
    public static void main(String args[]) {

            Scanner scn = new Scanner(System.in);

            int n = scn.nextInt();
            int[][] board = new int[n][n];

            for (int i = 0; i < board.length; i++) {
                for (int j = 0; j < board[0].length; j++) {
                    board[i][j] = scn.nextInt();
                }
                // System.out.println();
            }

            Sudoku(board, 0, 0);

            display(board);
        }

        public static boolean Sudoku(int[][] board, int row, int col) {

            if (col == board[0].length) {
                row = row + 1;
                col = 0;
            }

            if (row == board.length) {
                // display(board);
                return true;
            }

            if (board[row][col] != 0) {
                return Sudoku(board, row, col + 1);

            }

            for (int i = 1; i <= 9; i++) {

                if (isItSafe(board, row, col, i)) {

                    board[row][col] = i;

                    boolean res = Sudoku(board, row, col + 1);

                    if (res)
                        return true;

                    board[row][col] = 0;

                }
            }

            return false;

        }

        public static boolean isItSafe(int[][] board, int row, int col, int val) {

            return isItSafeRow(board, row, val) && isItSafeCol(board, col, val) && isItSafeCell(board, row, col, val);
        }

        public static boolean isItSafeRow(int[][] board, int row, int val) {

            for (int col = 0; col < board[0].length; col++) {
                if (board[row][col] == val) {
                    return false;
                }
            }

            return true;
        }

        public static boolean isItSafeCol(int[][] board, int col, int val) {

            for (int row = 0; row < board.length; row++) {
                if (board[row][col] == val) {
                    return false;
                }
            }

            return true;
        }

        public static boolean isItSafeCell(int[][] board, int row, int col, int val) {

            int rs = row - row % 3;
            int cs = col - col % 3;

            for (int r = rs; r < rs + 3; r++) {
                for (int c = cs; c < cs + 3; c++) {

                    if (board[r][c] == val) {
                        return false;
                    }
                }
            }

            return true;
        }

        public static void display(int[][] board) {

            for (int i = 0; i < board.length; i++) {
                for (int j = 0; j < board[0].length; j++) {
                    System.out.print(board[i][j] + " ");
                }
                System.out.println();
            }
        }
    }