[백준] 1389번 : 케빈 베이컨의 6단계 법칙 - Java(자바)

https://www.acmicpc.net/problem/1389

import java.util.*;

public class Main {
    static int arr[][];
    static boolean check[];
    static int n;
    
    static int bfs(int a){
        check=new boolean[n+1];
        Queue<int[]> q=new LinkedList<>();
        q.add(new int[]{a,0});
        check[a]=true;
        int sum=0;
        
        while(!q.isEmpty()){
            int v[]=q.poll();
            sum+=v[1];
            for(int i=1;i<=n;i++){
                if(arr[v[0]][i]==1 && check[i]==false){
                    check[i]=true;
                    q.add(new int[]{i,v[1]+1});
                }
            }
        }
        return sum;
    }
    
    public static void main(String args[]) {
        Scanner s=new Scanner(System.in);
        n=s.nextInt();
        int m=s.nextInt();
        arr=new int[n+1][n+1];
        while(m-->0){
            int a=s.nextInt();
            int b=s.nextInt();
            arr[a][b]=arr[b][a]=1;
        }
        int count=1000;
        int ans=0;
        for(int i=1;i<=n;i++){
            int sum=bfs(i);
            if(count>sum){
                count=sum;
                ans=i;
            }
        }
        System.out.print(ans);
    }
}