#1743 음식물 피하기 파이썬

www.acmicpc.net/problem/1743

1743번: 음식물 피하기

from collections import deque

n, m , k = map(int,input().split()) # 세로 가로 음식물 수 
graph = [ [0]*m for i in range(n)]
for i in range(k):
  a,b = map(int,input().split())
  graph[a-1][b-1] = 1 


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

def bfs(x,y):
  q = deque()
  q.append((x,y))
  graph[x][y] = 0 
  cnt = 1 

  while q : 
    a, b= q.popleft()
    for i in range(4):
      nx = a + dx[i]
      ny = b + dy[i]

      if nx<0 or nx>=n or ny<0 or ny>=m : 
        continue 
      if graph[nx][ny] == 1:
        cnt += 1 
        q.append((nx,ny))
        graph[nx][ny] = 0 
  return cnt 

tmp = 0 

for i in range(n):
  for j in range(m):
    if graph[i][j] != 0 :
      tmp = max(tmp, bfs(i,j))

print(tmp)