[백준] 종이의 개수 1780 - JAVA

문제

https://www.acmicpc.net/problem/1780

1780번: 종이의 개수

 

코드

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

public class Main {
	
	static int n;
	static int board[][];
	static int answer[] = new int [3];
	
	public static void main(String args[]) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		StringTokenizer st;
		
		n = Integer.parseInt(br.readLine());
		
		board = new int [n][n];
		
		for(int i=0;i<n;i++) {
			st = new StringTokenizer(br.readLine());
			for(int j=0;j<n;j++) {
				board[i][j] = Integer.parseInt(st.nextToken());
			}
		}
		
		recursion(n, 0, 0);
		
		for(int i=0;i<3;i++) {
			System.out.println(answer[i]);
		}
	}
	
	static void recursion(int k, int r, int c) {
		if(equalPaper(k, r, c)) {
			answer[board[r][c] + 1] += 1;
			return;
		}
		for(int i=0;i<3;i++) {
			for(int j=0;j<3;j++) {
				recursion(k/3, r + (k / 3 *i), c + (k / 3 * j) );
			}
		}
		
		
	}
	
	static boolean equalPaper(int k, int r, int c) {
		for(int i=r;i<r+k;i++) {
			for(int j=c;j<c+k;j++) {
				if(board[i][j] != board[r][c])
					return false;
			}
		}
		return true;
	}
}