스도쿠 - 2239번

 

---

내 코드

package com.company;

import java.io.*;
import java.util.*;

public class Main {
    static boolean[][] visitedA, visitedB, visitedC;
    static int[][] arr;
    static List<int[]> list;
    static boolean check;

    public static void main(String[] args) throws IOException {

        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

        arr = new int[9][9];
        visitedA = new boolean[9][10];
        visitedB = new boolean[9][10];
        visitedC = new boolean[9][10];
        list = new ArrayList<>();
        check = false;

        for (int i = 0; i < 9; i++) {
            String s = br.readLine();
            for (int j = 0; j < 9; j++) {
                arr[i][j] = s.charAt(j) - '0';

                if (arr[i][j] != 0) {
                    visitedA[i][arr[i][j]] = true;
                    visitedB[j][arr[i][j]] = true;
                    visitedC[(i / 3) * 3 + j / 3][arr[i][j]] = true;
                } else {
                    list.add(new int[]{i, j});
                }
            }
        }

        dfs(0, 0);
    }

    static void dfs(int index, int count) {

        if (check)
            return;

        if (count == list.size()) {
            for (int[] a : arr) {
                for (int i : a) {
                    System.out.print(i);
                }
                System.out.println();
            }
            check = true;
            return;
        }

        int[] node = list.get(index);

        for (int i = 1; i < 10; i++) {

            if (!visitedA[node[0]][i] && !visitedB[node[1]][i] && !visitedC[(node[0] / 3) * 3 + node[1] / 3][i]) {
                visitedA[node[0]][i]= true;
                visitedB[node[1]][i] = true;
                visitedC[(node[0] / 3) * 3 + node[1] / 3][i] = true;
                arr[node[0]][node[1]] = i;

                dfs(index + 1, count + 1);

                arr[node[0]][node[1]] = 0;
                visitedA[node[0]][i]= false;
                visitedB[node[1]][i] = false;
                visitedC[(node[0] / 3) * 3 + node[1] / 3][i] = false;
            }
        }

    }

}