[BOJ] 백준 2667 단지번호붙이기

[문제]

https://www.acmicpc.net/problem/2667

 

 

[소스 코드]

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


public class Main {
	static int n;
	static int[][] map;
	static boolean[][] visit;
	static int[] dr = {-1,1,0,0};
	static int[] dc = {0,0,-1,1};
	public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		n = Integer.parseInt(br.readLine());
		map = new int[n][n];
		for(int i=0;i<n;i++) {
			String s = br.readLine();
			for(int j=0;j<n;j++) {
				map[i][j] = s.charAt(j) - '0';
			}
		}
		visit = new boolean[n][n];
		PriorityQueue<Integer> pq = new PriorityQueue<>();
		for(int i=0;i<n;i++) {
			for(int j=0;j<n;j++) {
				if(!visit[i][j] && map[i][j]==1) {
					pq.offer(bfs(i,j,1));
				}
			}
		}
		System.out.println(pq.size());
		while(!pq.isEmpty()) {
			System.out.println(pq.poll());
		}
	}
	static int bfs(int i,int j,int idx) {
		Queue<int[]> q = new LinkedList<>();
		visit[i][j] = true;
		q.offer(new int[] {i,j});
		int cnt = 1;
		while(!q.isEmpty()) {
			int[] curr = q.poll();
			for(int d=0;d<4;d++) {
				int nr = curr[0] + dr[d];
				int nc = curr[1] + dc[d];
				if(nr<0 || nr>=n || nc<0 || nc>=n || visit[nr][nc]) continue;
				if(map[nr][nc]==1) {
					visit[nr][nc] = true;
					q.offer(new int[] {nr,nc});
					cnt++;
				}
			}
		}
		return cnt;
	}
}