Buggy python submission (verdict: Time Limit Exceeded):
from collections import deque

h, w = map(int, input().split())
c = list(map(lambda x: int(x)+1, input().split()))
d = list(map(lambda x: int(x)+1, input().split()))
s = ['#'*(w+4)]*2 + ['#'*2 + input() + '#'*2 for _ in range(h)] + ['#'*(w+4)]*2

ans = [[-1]*(w+4) for _ in range(h+4)]
for i in range(h+4):
    for j in range(w+4):
        if s[i][j] == '#':
            ans[i][j] = -2
ans[c[0]][c[1]] = 0

move1 = [(0, 1), (0, -1), (1, 0), (-1, 0)]
move2 = [(i, j) for i in range(-2, 3) for j in range(-2, 3) if abs(i)+abs(j) > 1]

yet = deque([(c[0], c[1])])
done = deque()

while yet:
    y, x = yet.popleft()
    done.append((y, x))
    for dy, dx in move1:
        ydy, xdx = y+dy, x+dx
        if ans[ydy][xdx] == -1:
            yet.append((ydy, xdx))
            ans[ydy][xdx] = ans[y][x]

    if len(yet) == 0:
        while done:
            y, x = done.popleft()
            for dy, dx in move2:
                ydy, xdx = y+dy, x+dx
                if ans[ydy][xdx] == -1:
                    ans[ydy][xdx] = ans[y][x] + 1
                    yet.append((ydy, xdx))

print(ans[d[0]][d[1]])

Fixed submission:
from collections import deque

h, w = map(int, input().split())
c = list(map(int, input().split()))
d = list(map(int, input().split()))
s = [list(input()) for _ in range(h)]

c = [i-1 for i in c]
d = [i-1 for i in d]

t0 = [(0, 1), (0, -1), (1, 0), (-1, 0)]
t1 = []
for i in range(-2, 3):
    for j in range(-2, 3):
        t1.append((i, j))
for i in t0:
    t1.remove(i)
t1.remove((0, 0))

check = [[-1]*w for _ in range(h)]
q = deque()
q.appendleft((c[0], c[1], 0))

while q:
    y, x, b = q.pop()
    if x == d[1] and y == d[0]:
        print(b)
        exit()
    if check[y][x] == -1:
        check[y][x] = b
        for dy, dx in t0:
            ydy, xdx = y+dy, x+dx
            if (0 <= xdx < w) and (0 <= ydy < h):
                if s[ydy][xdx] == '.' and check[ydy][xdx] == -1:
                    q.append((ydy, xdx, b))
        for dy, dx in t1:
            ydy, xdx = y+dy, x+dx
            if (0 <= xdx < w) and (0 <= ydy < h):
                if s[ydy][xdx] == '.' and check[ydy][xdx] == -1:
                    q.appendleft((ydy, xdx, b+1))
print(-1)

Buggy python submission (verdict: Time Limit Exceeded):
from collections import deque


H, W = map(int, input().split())
Ch, Cw = map(lambda x: int(x) - 1, input().split())
Dh, Dw = map(lambda x: int(x) - 1, input().split())
maze = [input() for _ in range(H)]

INF = 10 ** 12
path = [[INF] * W for _ in range(H)]  # path: 各マスへの移動コスト

# walk:移動A, warp:移動B
walk = [(0, 1), (0, -1), (-1, 0), (1, 0)]
warp = [(i, j) for i in range(-2, 3) for j in range(-2, 3) if (i, j) not in [(0, 0)] + walk]

q = deque()
path[Ch][Cw] = 0
q.append((Ch, Cw, 0))

while q:
    x, y, s = q.popleft()
    for dx, dy in walk:  # 移動A
        nx = x + dx
        ny = y + dy
        if 0 <= nx < H and 0 <= ny < W and maze[nx][ny] == '.' and path[nx][ny] > s:
            path[nx][ny] = s
            q.appendleft((nx, ny, s))  # 移動Aの場合はコスト0. キューの先頭に追加する.
    for dx, dy in warp:  # 移動B
        nx = x + dx
        ny = y + dy
        if 0 <= nx < H and 0 <= ny < W and maze[nx][ny] == '.' and path[nx][ny] > s + 1:
            path[nx][ny] = s + 1
            q.append((nx, ny, s + 1))  # 移動Bの場合はコスト1. キューの最後尾に追加する.
    
ans = path[Dh][Dw] if path[Dh][Dw] < INF else '-1'
print(ans)

Fixed submission:
from collections import deque

h, w = map(int, input().split())
c = list(map(int, input().split()))
d = list(map(int, input().split()))
s = [list(input()) for _ in range(h)]

c = [i-1 for i in c]
d = [i-1 for i in d]

t0 = [(0, 1), (0, -1), (1, 0), (-1, 0)]
t1 = []
for i in range(-2, 3):
    for j in range(-2, 3):
        t1.append((i, j))
for i in t0:
    t1.remove(i)
t1.remove((0, 0))

check = [[-1]*w for _ in range(h)]
q = deque()
q.appendleft((c[0], c[1], 0))

while q:
    y, x, b = q.pop()
    if x == d[1] and y == d[0]:
        print(b)
        exit()
    if check[y][x] == -1:
        check[y][x] = b
        for dy, dx in t0:
            ydy, xdx = y+dy, x+dx
            if (0 <= xdx < w) and (0 <= ydy < h):
                if s[ydy][xdx] == '.' and check[ydy][xdx] == -1:
                    q.append((ydy, xdx, b))
        for dy, dx in t1:
            ydy, xdx = y+dy, x+dx
            if (0 <= xdx < w) and (0 <= ydy < h):
                if s[ydy][xdx] == '.' and check[ydy][xdx] == -1:
                    q.appendleft((ydy, xdx, b+1))
print(-1)

Buggy python submission (verdict: Time Limit Exceeded):
def main():
    from collections import deque
    import sys
    readline = sys.stdin.buffer.readline

    h, w = map(int, readline().split())
    c = list(map(lambda x: int(x)+1, readline().split()))
    d = list(map(lambda x: int(x)+1, readline().split()))
    s = ['#'*(w+4)]*2 + ['#'*2 + readline().rstrip().decode('utf-8') + '#'*2 for _ in range(h)] + ['#'*(w+4)]*2

    t0 = [(0, 1), (0, -1), (1, 0), (-1, 0)]
    t1 = [(i, j) for i in range(-2, 3) for j in range(-2, 3) if abs(i)+abs(j) > 1]

    INF = float('inf')
    check = [[INF]*(w+4) for _ in range(h+4)]
    q = deque([(c[0], c[1], 0)])

    while q:
        y, x, b = q.pop()
        if y == d[0] and x == d[1]:
            print(b)
            exit()
        for dy, dx in t0:
            ydy, xdx = y+dy, x+dx
            if s[ydy][xdx] == '.' and b < check[ydy][xdx]:
                check[ydy][xdx] = b
                q.append((ydy, xdx, b))
        for dy, dx in t1:
            ydy, xdx = y+dy, x+dx
            if s[ydy][xdx] == '.' and b+1 < check[ydy][xdx]:
                check[ydy][xdx] = b+1
                q.appendleft((ydy, xdx, b+1))
    print(-1)

main()

Fixed submission:
from collections import deque

h, w = map(int, input().split())
c = list(map(int, input().split()))
d = list(map(int, input().split()))
s = [list(input()) for _ in range(h)]

c = [i-1 for i in c]
d = [i-1 for i in d]

t0 = [(0, 1), (0, -1), (1, 0), (-1, 0)]
t1 = []
for i in range(-2, 3):
    for j in range(-2, 3):
        t1.append((i, j))
for i in t0:
    t1.remove(i)
t1.remove((0, 0))

check = [[-1]*w for _ in range(h)]
q = deque()
q.appendleft((c[0], c[1], 0))

while q:
    y, x, b = q.pop()
    if x == d[1] and y == d[0]:
        print(b)
        exit()
    if check[y][x] == -1:
        check[y][x] = b
        for dy, dx in t0:
            ydy, xdx = y+dy, x+dx
            if (0 <= xdx < w) and (0 <= ydy < h):
                if s[ydy][xdx] == '.' and check[ydy][xdx] == -1:
                    q.append((ydy, xdx, b))
        for dy, dx in t1:
            ydy, xdx = y+dy, x+dx
            if (0 <= xdx < w) and (0 <= ydy < h):
                if s[ydy][xdx] == '.' and check[ydy][xdx] == -1:
                    q.appendleft((ydy, xdx, b+1))
print(-1)

Buggy python submission (verdict: Time Limit Exceeded):
def main():
    from collections import deque
    import sys
    readline = sys.stdin.buffer.readline

    h, w = map(int, readline().split())
    c = list(map(int, readline().split()))
    d = list(map(int, readline().split()))
    s = ['#'*(w+4)]*2 + ['#'*2 + readline().rstrip().decode('utf-8') + '#'*2 for _ in range(h)] + ['#'*(w+4)]*2

    c = [i-1+2 for i in c]
    d = [i-1+2 for i in d]

    t0 = [(0, 1), (0, -1), (1, 0), (-1, 0)]
    t1 = []
    for i in range(-2, 3):
        for j in range(-2, 3):
            t1.append((i, j))
    for i in t0:
        t1.remove(i)
    t1.remove((0, 0))

    check = [[-1]*(w+4) for _ in range(h+4)]
    q = deque()
    q.appendleft((c[0], c[1], 0))

    while q:
        y, x, b = q.pop()
        if y == d[0] and x == d[1]:
            print(b)
            exit()
        if check[y][x] == -1:
            check[y][x] = b
            for dy, dx in t0:
                ydy, xdx = y+dy, x+dx
                if s[ydy][xdx] == '.' and check[ydy][xdx] == -1:
                    q.append((ydy, xdx, b))
            for dy, dx in t1:
                ydy, xdx = y+dy, x+dx
                if s[ydy][xdx] == '.' and check[ydy][xdx] == -1:
                    q.appendleft((ydy, xdx, b+1))
    print(-1)

main()

Fixed submission:
from collections import deque

h, w = map(int, input().split())
c = list(map(int, input().split()))
d = list(map(int, input().split()))
s = [list(input()) for _ in range(h)]

c = [i-1 for i in c]
d = [i-1 for i in d]

t0 = [(0, 1), (0, -1), (1, 0), (-1, 0)]
t1 = []
for i in range(-2, 3):
    for j in range(-2, 3):
        t1.append((i, j))
for i in t0:
    t1.remove(i)
t1.remove((0, 0))

check = [[-1]*w for _ in range(h)]
q = deque()
q.appendleft((c[0], c[1], 0))

while q:
    y, x, b = q.pop()
    if x == d[1] and y == d[0]:
        print(b)
        exit()
    if check[y][x] == -1:
        check[y][x] = b
        for dy, dx in t0:
            ydy, xdx = y+dy, x+dx
            if (0 <= xdx < w) and (0 <= ydy < h):
                if s[ydy][xdx] == '.' and check[ydy][xdx] == -1:
                    q.append((ydy, xdx, b))
        for dy, dx in t1:
            ydy, xdx = y+dy, x+dx
            if (0 <= xdx < w) and (0 <= ydy < h):
                if s[ydy][xdx] == '.' and check[ydy][xdx] == -1:
                    q.appendleft((ydy, xdx, b+1))
print(-1)

Buggy python submission (verdict: Time Limit Exceeded):
from collections import deque

h, w = map(int, input().split())
c = list(map(int, input().split()))
d = list(map(int, input().split()))
s = ['#'*(w+4)]*2 + ['#'*2 + input() + '#'*2 for _ in range(h)] + ['#'*(w+4)]*2

c = [i-1+2 for i in c]
d = [i-1+2 for i in d]

t0 = [(0, 1), (0, -1), (1, 0), (-1, 0)]
t1 = []
for i in range(-2, 3):
    for j in range(-2, 3):
        t1.append((i, j))
for i in t0:
    t1.remove(i)
t1.remove((0, 0))

check = [[-1]*(w+4) for _ in range(h+4)]
q = deque()
q.appendleft((c[0], c[1], 0))

while q:
    y, x, b = q.pop()
    if y == d[0] and x == d[1]:
        print(b)
        exit()
    if check[y][x] == -1:
        check[y][x] = b
        for dy, dx in t0:
            ydy, xdx = y+dy, x+dx
            if s[ydy][xdx] == '.' and check[ydy][xdx] == -1:
                q.append((ydy, xdx, b))
        for dy, dx in t1:
            ydy, xdx = y+dy, x+dx
            if s[ydy][xdx] == '.' and check[ydy][xdx] == -1:
                q.appendleft((ydy, xdx, b+1))
print(-1)


Fixed submission:
from collections import deque

h, w = map(int, input().split())
c = list(map(int, input().split()))
d = list(map(int, input().split()))
s = [list(input()) for _ in range(h)]

c = [i-1 for i in c]
d = [i-1 for i in d]

t0 = [(0, 1), (0, -1), (1, 0), (-1, 0)]
t1 = []
for i in range(-2, 3):
    for j in range(-2, 3):
        t1.append((i, j))
for i in t0:
    t1.remove(i)
t1.remove((0, 0))

check = [[-1]*w for _ in range(h)]
q = deque()
q.appendleft((c[0], c[1], 0))

while q:
    y, x, b = q.pop()
    if x == d[1] and y == d[0]:
        print(b)
        exit()
    if check[y][x] == -1:
        check[y][x] = b
        for dy, dx in t0:
            ydy, xdx = y+dy, x+dx
            if (0 <= xdx < w) and (0 <= ydy < h):
                if s[ydy][xdx] == '.' and check[ydy][xdx] == -1:
                    q.append((ydy, xdx, b))
        for dy, dx in t1:
            ydy, xdx = y+dy, x+dx
            if (0 <= xdx < w) and (0 <= ydy < h):
                if s[ydy][xdx] == '.' and check[ydy][xdx] == -1:
                    q.appendleft((ydy, xdx, b+1))
print(-1)

Buggy python submission (verdict: Time Limit Exceeded):
def main():
    import sys
    readline = sys.stdin.buffer.readline

    from collections import deque

    h, w = map(int, readline().split())
    c = list(map(int, readline().split()))
    d = list(map(int, readline().split()))
    s = [readline().rstrip().decode('utf-8') for _ in range(h)]

    c = [i-1 for i in c]
    d = [i-1 for i in d]

    t0 = [(0, 1), (0, -1), (1, 0), (-1, 0)]
    t1 = []
    for i in range(-2, 3):
        for j in range(-2, 3):
            t1.append((i, j))
    for i in t0:
        t1.remove(i)
    t1.remove((0, 0))

    check = [[-1]*w for _ in range(h)]
    q = deque()
    q.appendleft((c[0], c[1], 0))

    while q:
        y, x, b = q.pop()
        if x == d[1] and y == d[0]:
            print(b)
            exit()
        if check[y][x] == -1:
            check[y][x] = b
            for dy, dx in t0:
                ydy, xdx = y+dy, x+dx
                if (0 <= xdx < w) and (0 <= ydy < h):
                    if s[ydy][xdx] == '.' and check[ydy][xdx] == -1:
                        q.append((ydy, xdx, b))
            for dy, dx in t1:
                ydy, xdx = y+dy, x+dx
                if (0 <= xdx < w) and (0 <= ydy < h):
                    if s[ydy][xdx] == '.' and check[ydy][xdx] == -1:
                        q.appendleft((ydy, xdx, b+1))
    print(-1)

main()

Fixed submission:
from collections import deque

h, w = map(int, input().split())
c = list(map(int, input().split()))
d = list(map(int, input().split()))
s = [list(input()) for _ in range(h)]

c = [i-1 for i in c]
d = [i-1 for i in d]

t0 = [(0, 1), (0, -1), (1, 0), (-1, 0)]
t1 = []
for i in range(-2, 3):
    for j in range(-2, 3):
        t1.append((i, j))
for i in t0:
    t1.remove(i)
t1.remove((0, 0))

check = [[-1]*w for _ in range(h)]
q = deque()
q.appendleft((c[0], c[1], 0))

while q:
    y, x, b = q.pop()
    if x == d[1] and y == d[0]:
        print(b)
        exit()
    if check[y][x] == -1:
        check[y][x] = b
        for dy, dx in t0:
            ydy, xdx = y+dy, x+dx
            if (0 <= xdx < w) and (0 <= ydy < h):
                if s[ydy][xdx] == '.' and check[ydy][xdx] == -1:
                    q.append((ydy, xdx, b))
        for dy, dx in t1:
            ydy, xdx = y+dy, x+dx
            if (0 <= xdx < w) and (0 <= ydy < h):
                if s[ydy][xdx] == '.' and check[ydy][xdx] == -1:
                    q.appendleft((ydy, xdx, b+1))
print(-1)

Buggy python submission (verdict: Time Limit Exceeded):
from collections import deque

h, w = map(int, input().split())
c = list(map(int, input().split()))
d = list(map(int, input().split()))
s = [list(input()) for _ in range(h)]

c = [i-1 for i in c]
d = [i-1 for i in d]

t0 = [(0, 1), (0, -1), (1, 0), (-1, 0)]
t1 = []
for i in range(-2, 3):
    for j in range(-2, 3):
        t1.append((i, j))
for i in t0:
    t1.remove(i)
t1.remove((0, 0))

check = [[-1]*w for _ in range(h)]
q = deque()
q.appendleft((c[0], c[1], 0))

while q:
    y, x, b = q.pop()
    if x == d[1] and y == d[0]:
        print(b)
        exit()
    if check[y][x] == -1:
        check[y][x] = b
        for dy, dx in t0:
            ydy, xdx = y+dy, x+dx
            if (0 <= xdx < w) and (0 <= ydy < h):
                if s[ydy][xdx] == '.' and check[ydy][xdx] == -1:
                    q.append((ydy, xdx, b))
        for dy, dx in t1:
            ydy, xdx = y+dy, x+dx
            if (0 <= xdx < w) and (0 <= ydy < h):
                if s[ydy][xdx] == '.' and check[ydy][xdx] == -1:
                    q.appendleft((ydy, xdx, b+1))
print(-1)


Fixed submission:
from collections import deque

h, w = map(int, input().split())
c = list(map(int, input().split()))
d = list(map(int, input().split()))
s = [list(input()) for _ in range(h)]

c = [i-1 for i in c]
d = [i-1 for i in d]

t0 = [(0, 1), (0, -1), (1, 0), (-1, 0)]
t1 = []
for i in range(-2, 3):
    for j in range(-2, 3):
        t1.append((i, j))
for i in t0:
    t1.remove(i)
t1.remove((0, 0))

check = [[-1]*w for _ in range(h)]
q = deque()
q.appendleft((c[0], c[1], 0))

while q:
    y, x, b = q.pop()
    if x == d[1] and y == d[0]:
        print(b)
        exit()
    if check[y][x] == -1:
        check[y][x] = b
        for dy, dx in t0:
            ydy, xdx = y+dy, x+dx
            if (0 <= xdx < w) and (0 <= ydy < h):
                if s[ydy][xdx] == '.' and check[ydy][xdx] == -1:
                    q.append((ydy, xdx, b))
        for dy, dx in t1:
            ydy, xdx = y+dy, x+dx
            if (0 <= xdx < w) and (0 <= ydy < h):
                if s[ydy][xdx] == '.' and check[ydy][xdx] == -1:
                    q.appendleft((ydy, xdx, b+1))
print(-1)