自己写的一个数独生成程序

import java.util.Random;


public class Shudu {
	private int[][] pan = new int[9][9];
	private final static int EASY = 20;
	private final static int NORMAL = 40;
	private final static int HARD = 60;
	
	public static void main(String[] args) {
		Shudu s = new Shudu();
		s.init();
		s.fillTheFirstRow();
		s.fillOtherCellAndCheck();
		s.sudoku(NORMAL);
		s.out();
	}
	//初始化各个值为0
	public void init() {
		for(int i = 0; i < 9; i++) {
			for(int j = 0; j < 9; j++) {
				pan[i][j] = 0;
			}
		}
	}
	
        //设置第一行的值，随机1-9
	public void fillTheFirstRow() {
		pan[0][random()] = 1;  
        for(int cellValue = 2; cellValue < 10; cellValue++){  
            int col = random();  
            while(pan[0][col] != 0){  
                col = random();  
            }  
            pan[0][col] = cellValue;  
        } 
	}
	
	public void fillOtherCellAndCheck() {
		int row = 1, col = 0;
		do {
			pan[row][col]++;
                        //如果为10的话表示失败，回退继续判断
			if(pan[row][col] == 10) {
				pan[row][col] = 0;
				col--;
				if(col < 0) {
					row--;
					col = 8;
				}
				continue; 
			}
                        //判断行中的数是否为1-9且不重复，成功则前进
			if(checkRow(row,col,pan[row][col])) {
				col++;
				if(col == 9) {
					row++;
					col = 0;
				}
			}
		}while(row < 9);
	}
	
	public int random() {
		Random random = new Random();
		return random.nextInt(9);
	}
	
	public boolean checkRow(int row, int col, int cellValue) {
		for(int i = 0; i < 9; i++) {
			if(i == col) {
				continue;
			}
			if(pan[row][i] == cellValue) {
				return false;
			}
		}
		return checkCol(row, col, cellValue);
	}
	
	public boolean checkCol(int row, int col, int cellValue) {
		for(int i = 0; i < 9; i++) {
			if(i == row) {
				continue;
			}
			if(pan[i][col] == cellValue) {
				return false;
			}
		}
		return checkSudoku(row, col, cellValue);
	}
	
	public boolean checkSudoku(int row, int col, int cellValue) {
		
		int n = row / 3;
		int m = col / 3;
        for(int i = n*3; i < 3*(n+1); i++){  
            for(int j = m*3; j < 3*(m+1); j++){  
                if(row== i && col == j) {
                	continue;  
                }
                if(pan[i][j] == cellValue) {
                	return false;  
                }
            }  
        }  
		return true;
	}
	//随机设置count个cell的值为0
	public void sudoku(int count) {
		for(int i = 0; i < count; i++) {
			int row = random();
			int col = random();
			while(pan[row][col] == 0) {
				row = random();
				col = random();
			}
			pan[row][col] = 0;
		}
	}
	
	public void out() {
		for(int i = 0; i < 9; i++) {
			for(int j = 0; j < 9; j++) {
				System.out.print(pan[i][j] + " ");
				if((j+1) % 3 == 0 && j != 8) {
					System.out.print(" ");
				}
				
				if(j == 8) {
					System.out.println("");
				}
			}
			if((i+1) % 3 == 0 && i != 8) {
				System.out.println("");
			}
		}
	}
}