[백준] 17086번 : 아기 상어2 - Python(파이썬)

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

import sys
sys.setrecursionlimit(10**6)
from collections import deque

dx=[0,0,1,-1,1,1,-1,-1]
dy=[1,-1,0,0,1,-1,-1,1]

def bfs(a,b):
    check=[[False for _ in range(m+1)] for _ in range(n+1)]
    q=deque()
    q.append((a,b,0))
    check[a][b]=True

    while len(q)>0:
        v0, v1, v2=list(q.popleft())

        for i in range(8):
            x=v0+dx[i]
            y=v1+dy[i]
            z=v2+1

            if x<0 or x>=n or y<0 or y>=m or check[x][y]==True: continue
            if arr[x][y]==1: return z
            q.append((x,y,z))
            check[x][y]=True
    return 0

n,m=map(int,input().split())
arr=[[0 for _ in range(m+1)] for _ in range(n+1)]
for i in range(n):
    st=list(map(int,input().split()))
    for j in range(m):
        arr[i][j]=st[j]

num=[]
for i in range(n):
    for j in range(m):
        if arr[i][j]!=1:
            num.append(bfs(i,j))

print(max(num))