백준 14502번 파이썬

from collections import deque

import copy

def bfs():

    queue=deque()

    gr=copy.deepcopy(g)

    global res

    for i in range(n):

        for j in range(m):

            if gr[i][j]==2:

                queue.append((i,j))

    while queue:

        x,y=queue.popleft()

        for i in range(4):

            nx=x+dx[i]

            ny=y+dy[i]

            if nx < 0 or nx >= n or ny < 0 or ny >= m:

                continue

            if gr[nx][ny]==0:

                gr[nx][ny]=2

                queue.append((nx,ny))

    cnt=0

    for e in range(n):

        for f in range(m):

            if gr[e][f]==0:

                cnt+=1

    res=max(res,cnt)

    

def check(num):

    if num==3:

        bfs()

        return

    for p in range(n):

        for q in range(m):

            

            if g[p][q]==0:

                g[p][q]=1

                check(num+1)

                g[p][q]=0

                

n,m=map(int,input().split())

res=0

g=[]

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

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

for i in range(n):

    g.append(list(map(int,input().split())))

check(0)

print(res)