DIY: Walls and Gates

Problem

You are given a $m \times n$ grid represented by a 2D array named rooms. The grid represents rooms where a cell can either be a wall, a gate, or an empty space. The rooms are initialized with these three possible values.

Values	Represents
$-1$	A wall or an obstacle
$0$	A gate
$2^{31} - 1 = 2147483647$	An empty room

For an empty room, you should assume that the distance to a gate is less than $2147483647$. We will call this value INF as an infinity value, where infinity represents an empty room.

Fill each empty room with the distance to its nearest gate. If it is impossible to reach a particular gate, you will fill it with the value INF.

Constraints:

• m == rooms.length
• n == rooms[i].length
• 1 <= m, n <= 250
• rooms[i][j] is $-1$, $0$, or $2^{31} - 1$.