프로그래머스 LV2 - 미로 탈출

문제 링크

풀이

from collections import deque

def is_valid_move(ny, nx, n, m, maps):
    return 0 <= ny < n and 0 <= nx < m and maps[ny][nx] != 'X'

def append_to_queue(ny, nx, k, time, visited, q):
    if not visited[ny][nx][k]:
        visited[ny][nx][k] = True
        q.append((ny, nx, k, time + 1))
             

def solution(maps):
    n, m = len(maps), len(maps[0])
    visited = [[[False for _ in range(2)] for _ in range(m)] for _ in range(n)]
    directions = [[-1,0], [1,0], [0,-1], [0, 1]]
    q = deque()
    end_y, end_x = -1, -1
    
    for i in range(n):
        for j in range(m):
            if maps[i][j] == 'S':
                q.append((i,j,0,0))
                visited[i][j][0] = True
            if maps[i][j] == 'E':
                end_y, end_x = i, j
    while q:
        y, x, k, time = q.popleft()
        
        if y == end_y and x == end_x and k == 1:
            return time
        
        for direction in directions:
            dx , dy = direction
            ny, nx = y + dy, x + dx
            if not is_valid_move(ny, nx, n, m, maps):
                continue
                
            if maps[ny][nx] == 'L':
                append_to_queue(ny, nx, 1, time, visited, q)
            else:
                append_to_queue(ny, nx, k, time, visited, q)
    return -1
                    

풀이 해석