佬们，py TLE 只能过两个点，还能怎么优化？

from math import inf
from collections import deque
import sys
n = int(sys.stdin.readline())
g = [sys.stdin.readline() for i in range(n)]
x1,y1,x2,y2 = [int(i) - 1 for i in sys.stdin.readline().split()]
vis = [[inf] * n for i in range(n)]
vis[x1][y1] = 0
quequ = deque()
quequ.append((x1,y1))
dirs = [(1,0),(-1,0),(0,-1),(0,1)]
while quequ:
    x,y = quequ.popleft()
    for dir in dirs:
        dx = x + dir[0]
        dy = y + dir[1]
        if 0 <= dx < n and 0 <= dy < n:
            if g[dx][dy] == '0' and vis[dx][dy] == inf:
                vis[dx][dy] = vis[x][y] + 1
                quequ.append((dx,dy))
print(vis[x2][y2] if vis[x2][y2] != inf else -1)