BFS(너비우선탐색) 알고리즘

package com.company;

import java.util.LinkedList;
import java.util.Queue;
import java.util.Scanner;

public class Main {

    static int N, E, startPoint;
    static int[][] graph;
    static int pos;
    static boolean[] visitied;

    static Scanner sc = new Scanner(System.in);

    public static void main(String[] args) {
       // write your code here
        N = sc.nextInt();
        E = sc.nextInt();
        startPoint = sc.nextInt();

        graph = new int[1001][1001];
        visitied = new boolean[N+1];


        //인접행렬을 완성
        int v1, v2;
        for(int i=1; i<=E; i++){
            v1 = sc.nextInt();
            v2 = sc.nextInt();

            graph[v1][v2] = 1;
            graph[v2][v1] = 1;
        }
        bfs(startPoint);
    }

    static void bfs(int startPoint){

        Queue<Integer> queue = new LinkedList<>();

        //시작지점 처리
        visitied[startPoint] = true;
        queue.offer(startPoint);


        while ( !queue.isEmpty() ){ //큐가 빌때까지 돈다

            pos = queue.poll();
            System.out.println(pos + " ");

            //인접영역 탐색
            for(int i=1; i<=E; i++){
                if( graph[pos][i]==1 && visitied[i]==false ){ //연결되어 있고 밤문하지 않은 경우
                    queue.offer(i);
                    visitied[i] = true;
                }
            }//for

        }//while
        
    }
}

*테스트 Case

4 5 1

1 2

1 3

1 4

2 4

3 4

=>1 2 3 4