백준-안전영역.py

from collections import deque
import sys

n = int(sys.stdin.readline())
maps =[]
dirs = [(-1,0),(1,0),(0,-1),(0,1)]

max_value = 0
for _ in range(n):
    arr = list(map(int, sys.stdin.readline().split()))
    max_value = max(max_value, max(arr))
    maps.append(arr)
    

def find_island(maps, visited, start, threshold):
    queue = deque()
    queue.append(start)
    while queue:
        y, x = queue.popleft()
        visited[y][x] = 1
        for dy, dx in dirs:
            if 0 <= y+dy < n and 0 <= x+dx < n and visited[y+dy][x+dx] == 0 and maps[y+dy][x+dx] > threshold:
                visited[y+dy][x+dx] = 1
                queue.append((y+dy, x+dx))
    return 1

answer = 0
for t in range(max_value):
    visited = [[0 for _ in range(n)] for _ in range(n)]
    result = 0
    for y in range(n):
        for x in range(n):
            if visited[y][x] == 0 and maps[y][x] > t:
                result += find_island(maps, visited, (y, x), t)
    answer = max(answer, result)
print(answer)