[PGS] 지게차와 크레인 - #83

from collections import deque

def solution(storage, requests):
    n, m = len(storage), len(storage[0])
    grid = [['.'] * (m + 2)]
    for row in storage:
        grid.append(['.'] + list(row) + ['.'])
    grid.append(['.'] * (m + 2))
    N, M = n + 2, m + 2

    for req in requests:
        if len(req) == 2:
            ch = req[0]
            for i in range(N):
                for j in range(M):
                    if grid[i][j] == ch:
                        grid[i][j] = '.'
        else:
            ch = req
            visited = [[False] * M for _ in range(N)]
            q = deque([(0, 0)])
            visited[0][0] = True
            outside = {(0, 0)}
            while q:
                y, x = q.popleft()
                for dy, dx in ((-1,0),(1,0),(0,-1),(0,1)):
                    ny, nx = y+dy, x+dx
                    if 0<=ny<N and 0<=nx<M and not visited[ny][nx] and grid[ny][nx]=='.':
                        visited[ny][nx] = True
                        outside.add((ny, nx))
                        q.append((ny, nx))
            to_remove = []
            for i in range(N):
                for j in range(M):
                    if grid[i][j] == ch:
                        for dy, dx in ((-1,0),(1,0),(0,-1),(0,1)):
                            if (i+dy, j+dx) in outside:
                                to_remove.append((i, j))
                                break
            for i, j in to_remove:
                grid[i][j] = '.'

    return sum(1 for row in grid for cell in row if cell != '.')