# Leetcode 529 Solution

https://leetcode.com/problems/minesweeper

## Solution

``````class Solution:
def updateBoard(self, board: List[List[str]], click: List[int]) -> List[List[str]]:
def within_board(board, i, j):
m = len(board)
n = len(board[0])
return 0 <= i < m and 0 <= j < n

i, j = click
if board[i][j] == 'M':
board[i][j] = 'X'
return board

q = collections.deque()
q.append((i, j))
seen = {(i, j)}

while q:
i, j = q.popleft()

nei_cnt = 0
nei_cnt += 1 if within_board(board, i - 1, j) and board[i - 1][j] == 'M' else 0
nei_cnt += 1 if within_board(board, i - 1, j - 1) and board[i - 1][j - 1] == 'M' else 0
nei_cnt += 1 if within_board(board, i - 1, j + 1) and board[i - 1][j + 1] == 'M' else 0
nei_cnt += 1 if within_board(board, i, j - 1) and board[i][j - 1] == 'M' else 0
nei_cnt += 1 if within_board(board, i, j + 1) and board[i][j + 1] == 'M' else 0
nei_cnt += 1 if within_board(board, i + 1, j - 1) and board[i + 1][j - 1] == 'M' else 0
nei_cnt += 1 if within_board(board, i + 1, j) and board[i + 1][j] == 'M' else 0
nei_cnt += 1 if within_board(board, i + 1, j + 1) and board[i + 1][j + 1] == 'M' else 0
board[i][j] = 'B' if nei_cnt == 0 else str(nei_cnt)

if nei_cnt == 0:
if within_board(board, i - 1, j) and (i - 1, j) not in seen and board[i - 1][j] == 'E':
q.append((i - 1, j))
if within_board(board, i - 1, j - 1) and (i - 1, j - 1) not in seen and board[i - 1][j - 1] == 'E':
q.append((i - 1, j - 1))
seen.add((i - 1, j - 1))
if within_board(board, i - 1, j + 1) and (i - 1, j + 1) not in seen and board[i - 1][j + 1] == 'E':
q.append((i - 1, j + 1))
seen.add((i - 1, j + 1))
if within_board(board, i, j - 1) and (i, j - 1) not in seen and board[i][j - 1] == 'E':
q.append((i, j - 1))
if within_board(board, i, j + 1) and (i, j + 1) not in seen and board[i][j + 1] == 'E':
q.append((i, j + 1))