** hello coders,** ** will you plz give me some intuition about the problem below:** ** i tried to solve it by solve it by dp with memoization recursively but showed max. depth reached error.**

Spiderman is stuck in a difficult situation. His arch enemy the Green Goblin has planted several of his infamous Pumpkin Bombs in various locations in a building. Help Spiderman activate his Spidey Sense and identify the impact zones. He has a blue print of the building which is a M x N matrix that is filled with the characters ‘O’, ‘B’, and ‘W’ where: ‘O’ represents an open space. ‘B’ represents a bomb. ‘W’ represents a wall. You have to replace all of the O’s (open spaces) in the matrix with their shortest distance from a bomb without being able to go through any walls. Also, replace the bombs with 0 and walls with -1 in the resultant matrix. If no path exists between a bomb and an open space replace the corresponding 'O' with -1.

Input: First line of input contains number of test cases T. For each testcase, first line contains space separated M and N respectively. Then M lines will follow containing N characters each.

Output: Print the resultant integer matrix that denotes shortest distance of each open space cell from a bomb in the blue print of the building.

Constraints: 0 <= T <= 50 1 <= M,N <= 10

Example: Sample Input: 1 3 3 O O O W B B W O O

Sample Output: 2 1 1 -1 0 0 -1 1 1

Explanation: The walls at (1,0) and (2,0) are replaced by -1. The bombs at (1,1) and (1,2) are replaced by 0. The impact zone for the bomb at (1,1) includes open spaces at index (0,0), (0,1) and (2,1) with distance from bomb calculated as 2,1,1 respectively. The impact zone for the bomb at (1,2) includes open spaces at index (0,3) and (2,2) with distance from bomb calculated as 1,1 respectively.

happy coding.