C#: Intuitive and Easy to Understand Solution. (Accepted)

[amandeep18feb]

public class Solution {
    private const int Gate = 0;
    private int[,] rooms;
    private int row;
    private int col;
    public void WallsAndGates(int[,] rooms) {
        this.rooms = rooms;
        this.row = this.rooms.GetLength(0);
        this.col = this.rooms.GetLength(1);
        for (int r = 0; r < this.row; r++)
            for (int c = 0; c < this.col; c++)  
                if (this.rooms[r, c] == Gate)                       
                    DFS(r, c, 0);
    }    
    private void DFS(int r, int c, int distance) {
        if (r < 0 || r >= this.row || c < 0 || c >= this.col || this.rooms[r, c] < distance)
            return;
        this.rooms[r, c] = distance;
        DFS(r + 1, c, distance + 1);
        DFS(r - 1, c, distance + 1);
        DFS(r, c + 1, distance + 1);
        DFS(r, c - 1, distance + 1);
    }
}