백준 1926번 그림 [ Java ]

1926번: 그림

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.*;

public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        int[] dx = new int[]{1, 0 , -1, 0};
        int[] dy = new int[]{0, 1, 0, -1};
        int[] nm = Arrays.stream(br.readLine().split(" ")).mapToInt(Integer::parseInt).toArray();
        String[][] field = new String[nm[0]][nm[1]];
        boolean[][] visited = new boolean[nm[0]][nm[1]];
        for (int i=0; i<nm[0]; i++) field[i] = br.readLine().split(" ");

        int num=0, max=0;
        for (int i=0; i<nm[0]; i++){
            for (int j=0; j<nm[1]; j++){
                if (field[i][j].equals("0") || visited[i][j]) continue;
                num++;
                ArrayList<int[]> Q = new ArrayList<>();
                visited[i][j] = true;
                Q.add(new int[]{i, j});
                int area = 0;
                while (!Q.isEmpty()){
                    area++;
                    int[] cur = Q.remove(0);
                    for (int dir = 0; dir<4; dir++){
                        int nx = cur[1] + dx[dir];
                        int ny = cur[0] + dy[dir];
                        if (nx<0 || nx>=nm[1] || ny<0 || ny>=nm[0]) continue;
                        if (visited[ny][nx] || !field[ny][nx].equals("1")) continue;
                        visited[ny][nx] = true;
                        Q.add(new int[]{ny, nx});
                    }
                }
                max = Math.max(max, area);
            }
        }
        System.out.print(num+"\n"+max);
    }
}