Buggy python submission (verdict: Runtime Error):
from collections import deque
import numpy as np


def bfs(h, w, board, visited):
    queue = deque([])
    for i in range(h):
        for j in range(w):
            if board[i][j] == "#":
                queue.append([i, j])
                visited[i][j] = 0
    while queue:
        y, x = queue.popleft()
        for i, j in ([1, 0], [0, 1], [-1, 0], [0, -1]):
            yn, xn = y+i, x+j
            if yn >= h or xn >= w or yn < 0 or xn < 0:
                continue
            if visited[yn][xn] == -1 and board[yn][xn] == ".":
                visited[yn][xn] = visited[y][x] + 1
                queue.append([yn, xn])

    return np.max(np.array(visited))


def main():
    h, w = map(int, input().split())
    board = [input() for _ in range(h)]
    visited = [[-1 for _ in range(w)] for _ in range(h)]
    print(bfs(h, w, board, visited))


if __name__ == "__main__":
    main()


Fixed submission:
from collections import deque


def bfs(h, w, board, visited):
    queue = deque([])
    for i in range(h):
        for j in range(w):
            if board[i][j] == "#":
                queue.append([i, j])
                visited[i][j] = 0
    ans = 0
    while queue:
        y, x = queue.popleft()
        for i, j in ([1, 0], [0, 1], [-1, 0], [0, -1]):
            yn, xn = y+i, x+j
            if yn >= h or xn >= w or yn < 0 or xn < 0:
                continue
            if visited[yn][xn] == -1 and board[yn][xn] == ".":
                visited[yn][xn] = visited[y][x] + 1
                queue.append([yn, xn])
                ans = max(ans, visited[yn][xn])

    return ans


def main():
    h, w = map(int, input().split())
    board = [input() for _ in range(h)]
    visited = [[-1 for _ in range(w)] for _ in range(h)]
    print(bfs(h, w, board, visited))


if __name__ == "__main__":
    main()

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


def bfs(h, w, board, visited):
    queue = deque([])
    for i in range(h):
        for j in range(w):
            if board[i][j] == "#":
                queue.append([i, j])
                visited[i][j] = 0
    while queue:
        y, x = queue.popleft()
        for i, j in ([1, 0], [0, 1], [-1, 0], [0, -1]):
            yn, xn = y+i, x+j
            if yn >= h or xn >= w or yn < 0 or xn < 0:
                continue
            if visited[yn][xn] == -1 and board[yn][xn] == ".":
                visited[yn][xn] = visited[y][x] + 1
                queue.append([yn, xn])

    return np.max(np.array(visited))


def main():
    h, w = map(int, input().split())
    board = [input() for _ in range(h)]
    visited = [[-1 for _ in range(w)] for _ in range(h)]
    print(bfs(h, w, board, visited))


if __name__ == "__main__":
    main()


Fixed submission:
from collections import deque


def bfs(h, w, board, visited):
    queue = deque([])
    for i in range(h):
        for j in range(w):
            if board[i][j] == "#":
                queue.append([i, j])
                visited[i][j] = 0
    ans = 0
    while queue:
        y, x = queue.popleft()
        for i, j in ([1, 0], [0, 1], [-1, 0], [0, -1]):
            yn, xn = y+i, x+j
            if yn >= h or xn >= w or yn < 0 or xn < 0:
                continue
            if visited[yn][xn] == -1 and board[yn][xn] == ".":
                visited[yn][xn] = visited[y][x] + 1
                queue.append([yn, xn])
                ans = max(ans, visited[yn][xn])

    return ans


def main():
    h, w = map(int, input().split())
    board = [input() for _ in range(h)]
    visited = [[-1 for _ in range(w)] for _ in range(h)]
    print(bfs(h, w, board, visited))


if __name__ == "__main__":
    main()

Buggy python submission (verdict: Runtime Error):
import numpy as np


def main():
    # H, W = [int(x) for x in input().split()]
    H, W = map(int, [int(x) for x in input().split()])
    board = [[0 for i in range(H)] for j in range(W)]

    """ #は1, .は0 """
    for i in range(H):
        X = input()
        X_len = len(X)
        for j in range(X_len):
            if X[j] == "#":
                board[i][j] = 1

    num_board = np.array(board)
    height, width = num_board.shape[:2]
    count = 0
    while (np.sum(num_board) != height*width):
        num_board_ans = np.zeros((height, width))
        for i in range(height):
            if np.sum(num_board[:, j]) == width:
                continue
            for j in range(width):
                if num_board[i, j] == 1:
                    num_board_ans[i, j] = 1
                    a = max(i-1, 0)
                    num_board_ans[a, j] = 1
                    b = max(j-1, 0)
                    num_board_ans[i, b] = 1
                    c = min(i+1, height-1)
                    num_board_ans[c, j] = 1
                    d = min(j+1, width-1)
                    num_board_ans[i, d] = 1
        num_board = num_board_ans
        count += 1

    print(count)


if __name__ == "__main__":
    main()


Fixed submission:
from collections import deque


def bfs(h, w, board, visited):
    queue = deque([])
    for i in range(h):
        for j in range(w):
            if board[i][j] == "#":
                queue.append([i, j])
                visited[i][j] = 0
    ans = 0
    while queue:
        y, x = queue.popleft()
        for i, j in ([1, 0], [0, 1], [-1, 0], [0, -1]):
            yn, xn = y+i, x+j
            if yn >= h or xn >= w or yn < 0 or xn < 0:
                continue
            if visited[yn][xn] == -1 and board[yn][xn] == ".":
                visited[yn][xn] = visited[y][x] + 1
                queue.append([yn, xn])
                ans = max(ans, visited[yn][xn])

    return ans


def main():
    h, w = map(int, input().split())
    board = [input() for _ in range(h)]
    visited = [[-1 for _ in range(w)] for _ in range(h)]
    print(bfs(h, w, board, visited))


if __name__ == "__main__":
    main()

Buggy python submission (verdict: Runtime Error):
import numpy as np


def main():
    # H, W = [int(x) for x in input().split()]
    H, W = map(int, [int(x) for x in input().split()])
    board = [[0 for i in range(H)] for j in range(W)]

    """ #は1, .は0 """
    for i in range(H):
        X = input()
        X_len = len(X)
        for j in range(X_len):
            if X[j] == "#":
                board[i][j] = 1

    num_board = np.array(board)
    height, width = num_board.shape[:2]
    count = 0
    while (np.sum(num_board) != height*width):
        num_board_ans = np.zeros((height, width))
        for i in range(height):
            for j in range(width):
                if num_board[i, j] == 1:
                    num_board_ans[i, j] = 1
                    a = max(i-1, 0)
                    num_board_ans[a, j] = 1
                    b = max(j-1, 0)
                    num_board_ans[i, b] = 1
                    c = min(i+1, height-1)
                    num_board_ans[c, j] = 1
                    d = min(j+1, width-1)
                    num_board_ans[i, d] = 1
        num_board = num_board_ans
        count += 1

    print(count)


if __name__ == "__main__":
    main()


Fixed submission:
from collections import deque


def bfs(h, w, board, visited):
    queue = deque([])
    for i in range(h):
        for j in range(w):
            if board[i][j] == "#":
                queue.append([i, j])
                visited[i][j] = 0
    ans = 0
    while queue:
        y, x = queue.popleft()
        for i, j in ([1, 0], [0, 1], [-1, 0], [0, -1]):
            yn, xn = y+i, x+j
            if yn >= h or xn >= w or yn < 0 or xn < 0:
                continue
            if visited[yn][xn] == -1 and board[yn][xn] == ".":
                visited[yn][xn] = visited[y][x] + 1
                queue.append([yn, xn])
                ans = max(ans, visited[yn][xn])

    return ans


def main():
    h, w = map(int, input().split())
    board = [input() for _ in range(h)]
    visited = [[-1 for _ in range(w)] for _ in range(h)]
    print(bfs(h, w, board, visited))


if __name__ == "__main__":
    main()

Buggy python submission (verdict: Runtime Error):
import numpy as np


def main():
    # H, W = [int(x) for x in input().split()]
    H, W = map(int, [int(x) for x in input().split()])
    board = [[0 for i in range(H)] for j in range(W)]

    """ #は1, .は0 """
    for i in range(H):
        X = input()
        for j in range(len(X)):
            if X[j] == "#":
                board[i][j] = 1

    num_board = np.array(board)
    height, width = num_board.shape[:2]
    count = 0
    while (np.sum(num_board) != height*width):
        num_board_ans = np.zeros((height, width))
        for i in range(height):
            for j in range(width):
                if num_board[i, j] == 1:
                    num_board_ans[i, j] = 1
                    a = max(i-1, 0)
                    num_board_ans[a, j] = 1
                    b = max(j-1, 0)
                    num_board_ans[i, b] = 1
                    c = min(i+1, height-1)
                    num_board_ans[c, j] = 1
                    d = min(j+1, width-1)
                    num_board_ans[i, d] = 1
        num_board = num_board_ans
        count += 1

    print(count)


if __name__ == "__main__":
    main()


Fixed submission:
from collections import deque


def bfs(h, w, board, visited):
    queue = deque([])
    for i in range(h):
        for j in range(w):
            if board[i][j] == "#":
                queue.append([i, j])
                visited[i][j] = 0
    ans = 0
    while queue:
        y, x = queue.popleft()
        for i, j in ([1, 0], [0, 1], [-1, 0], [0, -1]):
            yn, xn = y+i, x+j
            if yn >= h or xn >= w or yn < 0 or xn < 0:
                continue
            if visited[yn][xn] == -1 and board[yn][xn] == ".":
                visited[yn][xn] = visited[y][x] + 1
                queue.append([yn, xn])
                ans = max(ans, visited[yn][xn])

    return ans


def main():
    h, w = map(int, input().split())
    board = [input() for _ in range(h)]
    visited = [[-1 for _ in range(w)] for _ in range(h)]
    print(bfs(h, w, board, visited))


if __name__ == "__main__":
    main()

Buggy python submission (verdict: Runtime Error):
import numpy as np


def main():
    # H, W = [int(x) for x in input().split()]
    H, W = map(int, [int(x) for x in input().split()])
    board = [[0 for i in range(H)] for j in range(W)]

    """ #は1, .は0 """
    for i in range(H):
        X = input()
        for j in range(len(X)):
            if X[j] == "#":
                board[i][j] = 1

    num_board = np.array(board)
    height, width = num_board.shape[:2]
    count = 0
    while (np.sum(np.array(board)) != height*width):
        num_board_ans = board
        for i in range(height):
            for j in range(width):
                if board[i][j] == 1:
                    num_board_ans[i][j] = 1
                    a = max(i-1, 0)
                    num_board_ans[a][j] = 1
                    b = max(j-1, 0)
                    num_board_ans[i][b] = 1
                    c = min(i+1, height-1)
                    num_board_ans[c][j] = 1
                    d = min(j+1, width-1)
                    num_board_ans[i][d] = 1
        board = num_board_ans
        count += 1

    print(count)


if __name__ == "__main__":
    main()


Fixed submission:
from collections import deque


def bfs(h, w, board, visited):
    queue = deque([])
    for i in range(h):
        for j in range(w):
            if board[i][j] == "#":
                queue.append([i, j])
                visited[i][j] = 0
    ans = 0
    while queue:
        y, x = queue.popleft()
        for i, j in ([1, 0], [0, 1], [-1, 0], [0, -1]):
            yn, xn = y+i, x+j
            if yn >= h or xn >= w or yn < 0 or xn < 0:
                continue
            if visited[yn][xn] == -1 and board[yn][xn] == ".":
                visited[yn][xn] = visited[y][x] + 1
                queue.append([yn, xn])
                ans = max(ans, visited[yn][xn])

    return ans


def main():
    h, w = map(int, input().split())
    board = [input() for _ in range(h)]
    visited = [[-1 for _ in range(w)] for _ in range(h)]
    print(bfs(h, w, board, visited))


if __name__ == "__main__":
    main()

Buggy python submission (verdict: Runtime Error):
import numpy as np


def main():
    # H, W = [int(x) for x in input().split()]
    H, W = map(int, [int(x) for x in input().split()])
    board = [[0 for i in range(H)] for j in range(W)]

    """ #は1, .は0 """
    for i in range(H):
        X = input()
        for j in range(len(X)):
            if X[j] == "#":
                board[i][j] = 1

    num_board = np.array(board)
    height, width = num_board.shape[:2]
    count = 0
    while (np.sum(num_board) != height*width):
        num_board_ans = np.zeros((height, width))
        for i in range(height):
            for j in range(width):
                if num_board[i, j] == 1:
                    num_board_ans[i, j] = 1
                    a = max(i-1, 0)
                    num_board_ans[a, j] = 1
                    b = max(j-1, 0)
                    num_board_ans[i, b] = 1
                    c = min(i+1, height-1)
                    num_board_ans[c, j] = 1
                    d = min(j+1, width-1)
                    num_board_ans[i, d] = 1
        num_board = num_board_ans
        count += 1

    print(count)


if __name__ == "__main__":
    main()


Fixed submission:
from collections import deque


def bfs(h, w, board, visited):
    queue = deque([])
    for i in range(h):
        for j in range(w):
            if board[i][j] == "#":
                queue.append([i, j])
                visited[i][j] = 0
    ans = 0
    while queue:
        y, x = queue.popleft()
        for i, j in ([1, 0], [0, 1], [-1, 0], [0, -1]):
            yn, xn = y+i, x+j
            if yn >= h or xn >= w or yn < 0 or xn < 0:
                continue
            if visited[yn][xn] == -1 and board[yn][xn] == ".":
                visited[yn][xn] = visited[y][x] + 1
                queue.append([yn, xn])
                ans = max(ans, visited[yn][xn])

    return ans


def main():
    h, w = map(int, input().split())
    board = [input() for _ in range(h)]
    visited = [[-1 for _ in range(w)] for _ in range(h)]
    print(bfs(h, w, board, visited))


if __name__ == "__main__":
    main()

Buggy python submission (verdict: Runtime Error):
import numpy as np


def main():
    H, W = [map(int, x) for x in input().split()]
    board = [[0 for i in range(H)] for j in range(W)]

    """ #は1, .は0 """
    for i in range(H):
        X = input()
        for j in range(len(X)):
            if X[j] == "#":
                board[i][j] = 1

    num_board = np.array(board)
    height, width = num_board.shape[:2]
    count = 0
    height_r, width_r = range(height), range(width)
    while (np.sum(num_board) != height*width):
        num_board_ans = np.zeros((height, width))
        for i in height_r:
            for j in width_r:
                if num_board[i, j] == 1:
                    num_board_ans[i, j] = 1
                    a = max(i-1, 0)
                    num_board_ans[a, j] = 1
                    b = max(j-1, 0)
                    num_board_ans[i, b] = 1
                    c = min(i+1, height-1)
                    num_board_ans[c, j] = 1
                    d = min(j+1, width-1)
                    num_board_ans[i, d] = 1
        num_board = num_board_ans
        count += 1

    print(count)


if __name__ == "__main__":
    main()


Fixed submission:
from collections import deque


def bfs(h, w, board, visited):
    queue = deque([])
    for i in range(h):
        for j in range(w):
            if board[i][j] == "#":
                queue.append([i, j])
                visited[i][j] = 0
    ans = 0
    while queue:
        y, x = queue.popleft()
        for i, j in ([1, 0], [0, 1], [-1, 0], [0, -1]):
            yn, xn = y+i, x+j
            if yn >= h or xn >= w or yn < 0 or xn < 0:
                continue
            if visited[yn][xn] == -1 and board[yn][xn] == ".":
                visited[yn][xn] = visited[y][x] + 1
                queue.append([yn, xn])
                ans = max(ans, visited[yn][xn])

    return ans


def main():
    h, w = map(int, input().split())
    board = [input() for _ in range(h)]
    visited = [[-1 for _ in range(w)] for _ in range(h)]
    print(bfs(h, w, board, visited))


if __name__ == "__main__":
    main()

Buggy python submission (verdict: Runtime Error):
import numpy as np


def main():
    H, W = [int(x) for x in input().split()]
    board = [[0 for i in range(H)] for j in range(W)]

    """ #は1, .は0 """
    for i in range(H):
        X = input()
        for j in range(len(X)):
            if X[j] == "#":
                board[i][j] = 1

    num_board = np.array(board)
    height, width = num_board.shape[:2]
    count = 0
    height_r, width_r = range(height), range(width)
    for _ in height*width:
        num_board_ans = np.zeros((height, width))
        for i in height_r:
            for j in width_r:
                if num_board[i, j] == 1:
                    num_board_ans[i, j] = 1
                    a = max(i-1, 0)
                    num_board_ans[a, j] = 1
                    b = max(j-1, 0)
                    num_board_ans[i, b] = 1
                    c = min(i+1, height-1)
                    num_board_ans[c, j] = 1
                    d = min(j+1, width-1)
                    num_board_ans[i, d] = 1
        num_board = num_board_ans
        count += 1
        if (np.sum(num_board) == height*width):
            break

    print(count)


if __name__ == "__main__":
    main()


Fixed submission:
from collections import deque


def bfs(h, w, board, visited):
    queue = deque([])
    for i in range(h):
        for j in range(w):
            if board[i][j] == "#":
                queue.append([i, j])
                visited[i][j] = 0
    ans = 0
    while queue:
        y, x = queue.popleft()
        for i, j in ([1, 0], [0, 1], [-1, 0], [0, -1]):
            yn, xn = y+i, x+j
            if yn >= h or xn >= w or yn < 0 or xn < 0:
                continue
            if visited[yn][xn] == -1 and board[yn][xn] == ".":
                visited[yn][xn] = visited[y][x] + 1
                queue.append([yn, xn])
                ans = max(ans, visited[yn][xn])

    return ans


def main():
    h, w = map(int, input().split())
    board = [input() for _ in range(h)]
    visited = [[-1 for _ in range(w)] for _ in range(h)]
    print(bfs(h, w, board, visited))


if __name__ == "__main__":
    main()

Buggy python submission (verdict: Runtime Error):
import numpy as np
import sys 


def main():
    H, W = [int(x) for x in sys.stdin.readline().split()]
    board = [[0 for i in range(H)] for j in range(W)]

    """ #は1, .は0 """
    for i in range(H):
        X = sys.stdin.readline()
        for j in range(len(X)):
            if X[j] == "#":
                board[i][j] = 1

    num_board = np.array(board)
    height, width = num_board.shape[:2]
    count = 0
    height_r, width_r = range(height), range(width)
    while (np.sum(num_board) != height*width):
        num_board_ans = np.zeros((height, width))
        for i in height_r:
            for j in width_r:
                if num_board[i, j] == 1:
                    num_board_ans[i, j] = 1
                    a = max(i-1, 0)
                    num_board_ans[a, j] = 1
                    b = max(j-1, 0)
                    num_board_ans[i, b] = 1
                    c = min(i+1, height-1)
                    num_board_ans[c, j] = 1
                    d = min(j+1, width-1)
                    num_board_ans[i, d] = 1
        num_board = num_board_ans
        count += 1

    print(count)


if __name__ == "__main__":
    main()


Fixed submission:
from collections import deque


def bfs(h, w, board, visited):
    queue = deque([])
    for i in range(h):
        for j in range(w):
            if board[i][j] == "#":
                queue.append([i, j])
                visited[i][j] = 0
    ans = 0
    while queue:
        y, x = queue.popleft()
        for i, j in ([1, 0], [0, 1], [-1, 0], [0, -1]):
            yn, xn = y+i, x+j
            if yn >= h or xn >= w or yn < 0 or xn < 0:
                continue
            if visited[yn][xn] == -1 and board[yn][xn] == ".":
                visited[yn][xn] = visited[y][x] + 1
                queue.append([yn, xn])
                ans = max(ans, visited[yn][xn])

    return ans


def main():
    h, w = map(int, input().split())
    board = [input() for _ in range(h)]
    visited = [[-1 for _ in range(w)] for _ in range(h)]
    print(bfs(h, w, board, visited))


if __name__ == "__main__":
    main()

Buggy python submission (verdict: Runtime Error):
import numpy as np
import sys 


def main():
    H, W = [int(x) for x in sys.stdin.readline.split()]
    board = [[0 for i in range(H)] for j in range(W)]

    """ #は1, .は0 """
    for i in range(H):
        X = sys.stdin.readline
        for j in range(len(X)):
            if X[j] == "#":
                board[i][j] = 1

    num_board = np.array(board)
    height, width = num_board.shape[:2]
    count = 0
    height_r, width_r = range(height), range(width)
    while (np.sum(num_board) != height*width):
        num_board_ans = np.zeros((height, width))
        for i in height_r:
            for j in width_r:
                if num_board[i, j] == 1:
                    num_board_ans[i, j] = 1
                    a = max(i-1, 0)
                    num_board_ans[a, j] = 1
                    b = max(j-1, 0)
                    num_board_ans[i, b] = 1
                    c = min(i+1, height-1)
                    num_board_ans[c, j] = 1
                    d = min(j+1, width-1)
                    num_board_ans[i, d] = 1
        num_board = num_board_ans
        count += 1

    print(count)


if __name__ == "__main__":
    main()


Fixed submission:
from collections import deque


def bfs(h, w, board, visited):
    queue = deque([])
    for i in range(h):
        for j in range(w):
            if board[i][j] == "#":
                queue.append([i, j])
                visited[i][j] = 0
    ans = 0
    while queue:
        y, x = queue.popleft()
        for i, j in ([1, 0], [0, 1], [-1, 0], [0, -1]):
            yn, xn = y+i, x+j
            if yn >= h or xn >= w or yn < 0 or xn < 0:
                continue
            if visited[yn][xn] == -1 and board[yn][xn] == ".":
                visited[yn][xn] = visited[y][x] + 1
                queue.append([yn, xn])
                ans = max(ans, visited[yn][xn])

    return ans


def main():
    h, w = map(int, input().split())
    board = [input() for _ in range(h)]
    visited = [[-1 for _ in range(w)] for _ in range(h)]
    print(bfs(h, w, board, visited))


if __name__ == "__main__":
    main()

Buggy python submission (verdict: Runtime Error):
import numpy as np


def main():
    H, W = [int(x) for x in input().split()]
    board = [[0 for i in range(H)] for j in range(W)]

    """ #は1, .は0 """
    for i in range(H):
        X = input()
        for j in range(len(X)):
            if X[j] == "#":
                board[i][j] = 1

    num_board = np.array(board)
    height, width = num_board.shape[:2]
    count = 0
    height_r, width_r = range(height), range(width)
    while (np.sum(num_board) != height*width):
        num_board_ans = np.zeros((height, width))
        for i in height_r:
            for j in width_r:
                if num_board[i, j] == 1:
                    num_board_ans[i, j] = 1
                    a = max(i-1, 0)
                    num_board_ans[a, j] = 1
                    b = max(j-1, 0)
                    num_board_ans[i, b] = 1
                    c = min(i+1, height-1)
                    num_board_ans[c, j] = 1
                    d = min(j+1, width-1)
                    num_board_ans[i, d] = 1
        num_board = num_board_ans
        count += 1

    print(count)


if __name__ == "__main__":
    main()


Fixed submission:
from collections import deque


def bfs(h, w, board, visited):
    queue = deque([])
    for i in range(h):
        for j in range(w):
            if board[i][j] == "#":
                queue.append([i, j])
                visited[i][j] = 0
    ans = 0
    while queue:
        y, x = queue.popleft()
        for i, j in ([1, 0], [0, 1], [-1, 0], [0, -1]):
            yn, xn = y+i, x+j
            if yn >= h or xn >= w or yn < 0 or xn < 0:
                continue
            if visited[yn][xn] == -1 and board[yn][xn] == ".":
                visited[yn][xn] = visited[y][x] + 1
                queue.append([yn, xn])
                ans = max(ans, visited[yn][xn])

    return ans


def main():
    h, w = map(int, input().split())
    board = [input() for _ in range(h)]
    visited = [[-1 for _ in range(w)] for _ in range(h)]
    print(bfs(h, w, board, visited))


if __name__ == "__main__":
    main()

Buggy python submission (verdict: Runtime Error):
import numpy as np


def main():
    H, W = [int(x) for x in input().split()]
    board = [[0 for i in range(H)] for j in range(W)]

    """ #は1, .は0 """
    for i in range(H):
        X = input()
        for j in range(len(X)):
            if X[j] == "#":
                board[i][j] = 1

    num_board = np.array(board)
    height, width = num_board.shape[:2]
    count = 0
    # (np.sum(num_board) != height*width)
    while True:
        num_board_ans = np.zeros((height, width))
        for i in range(height):
            for j in range(width):
                if num_board[i, j] == 1:
                    num_board_ans[i, j] = 1
                    a = max(i-1, 0)
                    num_board_ans[a, j] = 1
                    b = max(j-1, 0)
                    num_board_ans[i, b] = 1
                    c = min(i+1, height-1)
                    num_board_ans[c, j] = 1
                    d = min(j+1, width-1)
                    num_board_ans[i, d] = 1
        num_board = num_board_ans
        count += 1
        if (np.sum(num_board) == height*width):
            break

    print(count)


if __name__ == "__main__":
    main()


Fixed submission:
from collections import deque


def bfs(h, w, board, visited):
    queue = deque([])
    for i in range(h):
        for j in range(w):
            if board[i][j] == "#":
                queue.append([i, j])
                visited[i][j] = 0
    ans = 0
    while queue:
        y, x = queue.popleft()
        for i, j in ([1, 0], [0, 1], [-1, 0], [0, -1]):
            yn, xn = y+i, x+j
            if yn >= h or xn >= w or yn < 0 or xn < 0:
                continue
            if visited[yn][xn] == -1 and board[yn][xn] == ".":
                visited[yn][xn] = visited[y][x] + 1
                queue.append([yn, xn])
                ans = max(ans, visited[yn][xn])

    return ans


def main():
    h, w = map(int, input().split())
    board = [input() for _ in range(h)]
    visited = [[-1 for _ in range(w)] for _ in range(h)]
    print(bfs(h, w, board, visited))


if __name__ == "__main__":
    main()

Buggy python submission (verdict: Runtime Error):
import numpy as np


def main():
    H, W = [int(x) for x in input().split()]
    board = [[0 for i in range(H)] for j in range(W)]

    """ #は1, .は0 """
    for i in range(H):
        X = input()
        for j in range(len(X)):
            if X[j] == "#":
                board[i][j] = 1

    num_board = np.array(board)
    height, width = num_board.shape[:2]
    count = 0
    while (np.sum(num_board) != height*width):
        num_board_ans = np.zeros((height, width))
        for i in range(height):
            for j in range(width):
                if num_board[i, j] == 1:
                    num_board_ans[i, j] = 1
                    a = max(i-1, 0)
                    num_board_ans[a, j] = 1
                    b = max(j-1, 0)
                    num_board_ans[i, b] = 1
                    c = min(i+1, height-1)
                    num_board_ans[c, j] = 1
                    d = min(j+1, width-1)
                    num_board_ans[i, d] = 1
        num_board = num_board_ans
        count += 1

    print(count)


if __name__ == "__main__":
    main()


Fixed submission:
from collections import deque


def bfs(h, w, board, visited):
    queue = deque([])
    for i in range(h):
        for j in range(w):
            if board[i][j] == "#":
                queue.append([i, j])
                visited[i][j] = 0
    ans = 0
    while queue:
        y, x = queue.popleft()
        for i, j in ([1, 0], [0, 1], [-1, 0], [0, -1]):
            yn, xn = y+i, x+j
            if yn >= h or xn >= w or yn < 0 or xn < 0:
                continue
            if visited[yn][xn] == -1 and board[yn][xn] == ".":
                visited[yn][xn] = visited[y][x] + 1
                queue.append([yn, xn])
                ans = max(ans, visited[yn][xn])

    return ans


def main():
    h, w = map(int, input().split())
    board = [input() for _ in range(h)]
    visited = [[-1 for _ in range(w)] for _ in range(h)]
    print(bfs(h, w, board, visited))


if __name__ == "__main__":
    main()