[規格]No 11724-接続要素数(JAVA)

接続要素とは?

コード（BFS使用）

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.LinkedList;
import java.util.Queue;

public class No11724_연결요소의개수 {
    static int[][] graph;
    static boolean[] visited;

    static int N;

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String temp[] = br.readLine().split(" ");
        N = Integer.parseInt(temp[0]); //정점의 개수
        int M = Integer.parseInt(temp[1]); //간선의 개수
        int conn =0; //연결요소의 개수

        graph= new int[N+1][N+1];
        visited = new boolean[N+1];

        for (int i=0;i<M;i++) {
            String s[] = br.readLine().split(" ");
            graph[Integer.parseInt(s[0])][Integer.parseInt(s[1])] =1;
            graph[Integer.parseInt(s[1])][Integer.parseInt(s[0])] =1;
        }

        for (int i=1;i<=N;i++) {
            if (!visited[i]) {
                bfs(i);
                conn++;
            }

        }

        System.out.println(conn);
    }

    public static void bfs (int n) {
        Queue<Integer> queue = new LinkedList<>();
        queue.add(n);
        visited[n] = true;

        while (!queue.isEmpty()) {
            int current = queue.poll();

            for (int i = 1; i <= N; i++) {
                if (visited[i] == false && graph[current][i] == 1) {
                    visited[i] = true;
                    queue.add(i);
                }

            }

        }

    }
}

難点