[Baekjoon Online Judge] 2583 - 영역 구하기 / Java

https://www.acmicpc.net/problem/2583

2583번: 영역 구하기

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Collections;
import java.util.StringTokenizer;

public class Main {

	static int M, N, K, cnt = 0;
	static int[][] map;
	static ArrayList<Integer> list = new ArrayList<>();
	static int[] dr = { -1, 1, 0, 0 };
	static int[] dc = { 0, 0, -1, 1 };

	public static void main(String[] args) throws Exception {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		StringTokenizer st = new StringTokenizer(br.readLine());

		M = Integer.parseInt(st.nextToken());
		N = Integer.parseInt(st.nextToken());
		K = Integer.parseInt(st.nextToken());
		map = new int[M][N];

		for (int i = 0; i < K; i++) {
			st = new StringTokenizer(br.readLine());
			int c1 = Integer.parseInt(st.nextToken());
			int r1 = Integer.parseInt(st.nextToken());
			int c2 = Integer.parseInt(st.nextToken());
			int r2 = Integer.parseInt(st.nextToken());

			for (int r = r1; r < r2; r++) {
				for (int c = c1; c < c2; c++) {
					map[r][c] = 1;
				}
			}
		}

		for (int i = 0; i < M; i++) {
			for (int j = 0; j < N; j++) {
				if (map[i][j] == 0) {
					cnt = 0;
					dfs(i, j);
					list.add(cnt);
				}
			}
		}

		Collections.sort(list);
		System.out.println(list.size());
		for (Integer i : list) {
			System.out.print(i + " ");
		}
	}

	private static void dfs(int r, int c) {
		map[r][c] = 1;
		cnt++;

		for (int dir = 0; dir < 4; dir++) {
			int nr = r + dr[dir];
			int nc = c + dc[dir];

			if ((nr >= 0 & nr < M && nc >= 0 && nc < N) && map[nr][nc] == 0) {
				dfs(nr, nc);
			}
		}
	}
}