Walls And Gates Python Solution with Tests

lcpy gen -n 286   # by problem number
lcpy gen -s walls_and_gates   # by problem name

Input: rooms = [[2147483647,-1,0,2147483647],[2147483647,2147483647,2147483647,-1],[2147483647,-1,2147483647,-1],[0,-1,2147483647,2147483647]]
Output: [[3,-1,0,1],[2,2,1,-1],[1,-1,2,-1],[0,-1,3,4]]

INF  -1   0   INF
INF  INF  INF  -1
INF  -1   INF  -1
  0  -1   INF  INF

 3  -1   0   1
 2   2   1  -1
 1  -1   2  -1
 0  -1   3   4

Input: rooms = [[0,-1],[2147483647,2147483647]]
Output: [[0,-1],[1,2]]

from collections import deque


class Solution:
    # Time: O(m * n)
    # Space: O(m * n)
    def walls_and_gates(self, rooms: list[list[int]]) -> None:
        if not rooms or not rooms[0]:
            return

        rows, cols = len(rooms), len(rooms[0])
        queue: deque[tuple[int, int]] = deque()
        for r in range(rows):
            for c in range(cols):
                if rooms[r][c] == 0:
                    queue.append((r, c))

        directions = [(1, 0), (-1, 0), (0, 1), (0, -1)]
        while queue:
            r, c = queue.popleft()
            for dr, dc in directions:
                nr, nc = r + dr, c + dc
                if 0 <= nr < rows and 0 <= nc < cols and rooms[nr][nc] == 2147483647:
                    rooms[nr][nc] = rooms[r][c] + 1
                    queue.append((nr, nc))