[백준] 17086번 : 아기 상어2 - C#

https://www.acmicpc.net/problem/17086

using System;
using System.Collections;

class Program
{
    static int[,] arr;
    static bool[,] check;
    static int n,m;
    static int[] dx= {0,0,1,-1,1,1,-1,-1};
	static int[] dy= {1,-1,0,0,1,-1,-1,1};
    
    static int bfs(int a,int b){
        check=new bool[n+1,m+1];
        Queue q=new Queue();
        q.Enqueue(new int[]{a,b,0});
        check[a,b]=true;
        
        while(q.Count!=0){
            int[] v=(int[])q.Dequeue();
            
            for(int i=0;i<8;i++){
                int x=v[0]+dx[i];
                int y=v[1]+dy[i];
                int z=v[2]+1;
                
                if(x<0 || x>=n || y<0 || y>=m || check[x,y]==true) continue;
                if(arr[x,y]==1) return z;
                q.Enqueue(new int[]{x,y,z});
                check[x,y]=true;
            }
        }
        return 0;
    }
    
    static void Main() {
        string[] s=Console.ReadLine().Split(' ');
        n=int.Parse(s[0]);
        m=int.Parse(s[1]);
        arr=new int[n+1,m+1];
        
        for(int i=0;i<n;i++){
            string[] s1=Console.ReadLine().Split(' ');
            for(int j=0;j<m;j++){
                arr[i,j]=int.Parse(s1[j]);
            }
        }
        int count=0;
        int num=0;
        for(int i=0;i<n;i++){
            for(int j=0;j<m;j++){
                if(arr[i,j]!=1){
                    num=bfs(i,j);
                    count=num>count?num:count;
                }
            }
        }
        Console.Write(count);
    }
}