-1 A wall or an obstacle.

0 A gate.

INF Infinity means an empty room. We use the value 2³¹ - 1 = 2147483647 to represent INF as you may assume that the distance to a gate is less than 2147483647.

Fill each empty room with the distance to its nearest gate. If it is impossible to reach a gate, it should be filled with INF.

Example 1:

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]]

Example 2:

Input: rooms = [[-1]]
Output: [[-1]]

Constraints:

m == rooms.length
n == rooms[i].length
1 <= m, n <= 250
rooms[i][j] is -1, 0, or 2³¹ - 1.

Walls and Gates

Problem Description

Problem Description

Answer Panel