Sudoku in Java

I have tried to given the best solution finder for SUDOKU and even i have added some stuff to display the solution. So you can have a look on both logic and display functionality.

Here is the solution in java:

import java.awt.EventQueue;

import java.awt.GridBagConstraints;

import java.awt.GridBagLayout;

import java.awt.Insets;

import javax.swing.JFrame;

import javax.swing.JPanel;

import javax.swing.JTextField;

public class MySudoku {   

       private final int[][] matrix;

       private final boolean solved;

       public MySudoku(int[][] matrix) {

              this.matrix = matrix;

              this.solved = solve(0, 0);

       }

       private boolean check(int row, int column, int value) {

              int boxRow = (row / 3) * 3;

              int boxColumn = (column / 3) * 3;

              for (int index = 0; index < 9; index++) {

                     if ((matrix[row][index] == value)// check the row

                                  || (matrix[index][column] == value) // check the column

                                  || (matrix[boxRow + (index % 3)][boxColumn + (index / 3)] == value)) {

                           // check the box

                           return false;

                     }

              }

              return true;

       }

       private boolean solve(int row, int column) {

              if (row == 9) {

                     row = 0;

                     column = column + 1;

                     if (column == 9) {

                           return true;

                     }

              }

              if (matrix[row][column] != 0) {// to skip the filled cells.

                     return solve(row + 1, column);

              }

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

                     if (check(row, column, value)) {

                           matrix[row][column] = value;

                           if (solve(row + 1, column)) {

                                  return true;

                           }

                     }

              }

              matrix[row][column] = 0; // this is playing import role to reset back.

              return false;

       }

       public void displaySolution() {

              if (solved) {

                     Runnable Runnable = new Runnable() {

                           public void run() {

                                  final JTextField[][] cells = new JTextField[9][9];

                                  final JPanel panel = new JPanel();

                                  final JFrame frame = new JFrame("Sudoku Board");

                                 

                                  for (int row = 0; row < 9; row++) {

                                         for (int col = 0; col < 9; col++) {

                                                cells[row][col] = new JTextField();

                                                cells[row][col].setText("  "

                                                              + String.valueOf(matrix[row][col]) + "  ");

                                                panel.add(cells[row][col]);

                                         }

                                  }

                                  frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

                                  frame.setLayout(new GridBagLayout());

                                  Insets insets = new Insets(0, 0, 0, 0);

                                  GridBagConstraints gbc = new GridBagConstraints(0, 0, 0, 0,

                                                1, 1, GridBagConstraints.CENTER,

                                                GridBagConstraints.BOTH, insets, 0, 0);

                                  frame.add(panel, gbc);

                                  frame.setSize(280, 280);

                                  frame.setVisible(true);

                           }

                     };

                     EventQueue.invokeLater(Runnable);

              } else {

                     System.out.println("No Solution Available.");

              }

       }

      

       public static void main(String[] args) {

              int[][] matrix = new int[][] { { 0, 8, 0, 4, 0, 2, 0, 6, 0 },

                           { 0, 3, 4, 0, 0, 0, 9, 1, 0 }, { 9, 6, 0, 0, 0, 0, 0, 8, 4 },

                           { 0, 0, 0, 2, 1, 6, 0, 0, 0 }, { 0, 0, 0, 0, 0, 0, 0, 0, 0 },

                           { 0, 0, 0, 3, 5, 7, 0, 0, 0 }, { 8, 4, 0, 0, 0, 0, 0, 7, 5 },

                           { 0, 2, 6, 0, 0, 0, 1, 3, 0 }, { 0, 9, 0, 7, 0, 1, 0, 4, 0 } };

              new MySudoku(matrix).displaySolution();

       }

}