22.01.24 - [BOJ] 1780. 종이의 개수

[suhyunsim]

문제

• 종이의 개수

핵심 아이디어

• 재귀

어려운 점, 실수

풀이

package main.java.com.poogle.BOJ.Q1780;

import java.util.Scanner;

public class Main {
    static int n;
    static int[][] board = new int[2200][2200];
    static int[] cnt = new int[3];

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        n = sc.nextInt();
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < n; j++) {
                board[i][j] = sc.nextInt();
            }
        }
        calculate(0, 0, n);

        for (int i : cnt) {
            System.out.println(i);
        }
    }

    private static void calculate(int x, int y, int z) {
        if (check(x, y, z)) {
            cnt[board[x][y] + 1] += 1;
            return;
        }
        int n = z / 3;
        for (int i = 0; i < 3; i++) {
            for (int j = 0; j < 3; j++) {
                calculate(x + i * n, y + j * n, n);
            }
        }

    }

    private static boolean check(int x, int y, int n) {
        for (int i = x; i < x + n; i++) {
            for (int j = y; j < y + n; j++) {
                if (board[i][j] != board[x][y]) return false;
            }
        }
        return true;
    }
}