题解 | 挡住洪水

import sys
from collections import deque

r,c = map(int,input().split())
data = []
for _ in range(r):
    data.append(list(input()))
dirs = [(1,0), (-1,0), (0,1), (0,-1)]
q = deque()
s = 0
for i in range(r):
    for j in range(c):
        if data[i][j] == '0':
            q = deque()
            flag = 1
            q.append((i,j))
            data[i][j] = '*'
            cnt = 0
            while q:
                x, y = q.popleft()
                if x==0 or y==0 or x==r-1 or y == c-1:
                    flag = 0
                cnt+=1
                for dx,dy in dirs:
                    nx, ny = x+dx, y+dy
                    if 0<=nx<r and 0<=ny<c and data[nx][ny]=='0':
                        q.append((nx,ny))
                        data[nx][ny] = '*'
            if flag:
                s+=cnt
print(s)