https://school.programmers.co.kr/learn/courses/30/lessons/43162

Problem

Code

import java.util.*;
class Solution {
    static int[] visited;
    
    public void DFS(int[][] arr, int d, int n) {
        for (int i=0; i<n; i++) {
            if (arr[d][i] == 1 && visited[i] == 0) {
                visited[i] = 1;
                DFS(arr, i, n);
            }
        }
    }
    
    public int solution(int n, int[][] computers) {
        int answer = 0;
        visited = new int[n];
        for (int i=0; i<n; i++) {
            if (visited[i] == 0) {
                visited[i] = 1;
                DFS(computers, i, n);
                answer++;
            }
        }
        
        return answer;
    }
}

Result