미로 탐색

미로 탐색 - BOJ

from collections import deque

n, m = map(int, input().split())
arr = [list(map(int, input())) for _ in range(n)]
q = deque()
visited = [[0] * m for _ in range(n)]
dist = [[0]*m for _ in range(n)]

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

q.append((0, 0))
visited[0][0] = 1
dist[0][0] = 1

while q:
    i, j = q.popleft()
    for a in range(4):
        ni, nj = i + dx[a], j + dy[a]
        if 0 <= ni < n and 0 <= nj < m:
            if visited[ni][nj] == 0 and arr[ni][nj] == 1:
                q.append((ni, nj))
                dist[ni][nj] = dist[i][j] + 1
                visited[ni][nj] = 1

print(dist[n-1][m-1])