Sudoku class

Sudoku.java

package sudoku;

import java.util.LinkedList;

public class Sudoku {

	public void DoSudoku(int [][] board, int row, int column) {
		if(isFinish(board)){showBoard(board); return;}
		if(row >= board.length) return;
		if(column >= board[row].length){
			DoSudoku(board, row + 1, 0);
		}
		
		if(board[row][column] != 0){ 
			DoSudoku(board, row, column + 1);
		}
		
		LinkedList<Integer> boardList = ListRules(board, row, column);
		while(!boardList.isEmpty()){
			board[row][column] = boardList.removeFirst();
			DoSudoku(board, row, column + 1);
			board[row][column] = 0;
		}	
	}
	
	private void showBoard(int[][] board) {
		for (int row = 0; row < board.length; row++) {
			for (int column = 0; column < board[row].length; column++) {
				System.out.print(board[row][column] + " ");
			}
			System.out.println("");
		}
	}

	private boolean isFinish(int[][] board) {
		for (int row = 0; row < board.length; row++) {
			for (int column = 0; column < board[row].length; column++) {
				if(board[row][column] != 0){
					return false;
				}
			}
		}
		return true;
	}

	public LinkedList<Integer> ListRules(int[][] board, int row, int column){
		int value = 1;
		LinkedList<Integer> list = new LinkedList<>();
		while(value <= board.length){
			if(inRow(board, row, value) 
					&& inColumn(board, column, value) 
					&& (inRegion(board, row, column, value))){
				list.add(value);
			}
			value += 1;
		}
		return list;
	}

	private boolean inRegion(int[][] board, int row, int column, int value) {
		int width = (int)Math.sqrt(board.length);
		int rowSize = (row/width) * width;
		int columnSize = (column/width) * width;
		int auxSize = rowSize;
		
		while(auxSize < auxSize + width){
			int tempSize = columnSize;
			while(tempSize < columnSize + width){
				if(board[row][column] == value) return true;
				tempSize += 1;
			}
			auxSize += 1;
		}
		
		return false;
	}

	private boolean inColumn(int[][] board, int position, int value) {
		int actual = 0;
		while(actual < board.length){
			if(board[actual][position] == value){
				return true;	
			}
			actual += 1;
		}
		return false;
	}

	private boolean inRow(int[][] board, int position, int value) {
		int actual = 0;
		while(actual < board[position].length){
			if(board[position][actual] == value) return true;
			actual += 1;
		}
		return false;
	}
	
}