数独

import java.util.Scanner;

//数独
public class Main {
	public static void main(String[] args) {
		Scanner sn = new Scanner(System.in);
		boolean[][] rows = new boolean[9][9]; // 行
		boolean[][] cols = new boolean[9][9]; // 列
		boolean[][] blocks = new boolean[9][9];  //块
		int[][] sd = new int[9][9];  //数独
		// 初始化
		for (int i = 0; i < 9; i++) {
			for (int j = 0; j < 9; j++) {
				sd[i][j] = sn.nextInt();
				if (sd[i][j] != 0) {
					rows[i][sd[i][j] - 1] = true;
					cols[sd[i][j] - 1][j] = true;
					blocks[i/3*3+j/3][sd[i][j]-1] = true;  //相应块的相应数字处更改值
				}
			}
		}
		dfs(sd,rows,cols,blocks);
		for(int i=0;i<9;i++){
			for(int j=0;j<9;j++){
				System.out.print(sd[i][j]+" ");
			}
			System.out.println();
		}

	}

	public static boolean dfs(int[][] sd, boolean[][] rows, boolean[][] cols,boolean[][] blocks) {
		for (int i = 0; i < 9; i++) {
			for (int j = 0; j < 9; j++) {
				if (sd[i][j] == 0) {
					for (int k = 0; k < 9; k++) {
						if (!rows[i][k] && !cols[k][j]&&!blocks[i/3*3+j/3][k]) {
							sd[i][j] = k + 1;
							rows[i][k] = cols[k][j] = blocks[i/3*3+j/3][k] = true;
							if (dfs(sd, rows, cols,blocks))
								return true;
							rows[i][k] = cols[k][j] =blocks[i/3*3+j/3][k] = false;
							sd[i][j] = 0;
						}
					}
					return false;
				}
			}
		}
		return true;
	}
}