Minimum Direction Changes Problem Statement

Given a 2D grid with 'N' rows and 'M' columns, where each cell contains a character from the set { 'U', 'L', 'D', 'R' } indicating the allowed direction to move to a neighboring cell, determine the minimum number of cells that need to be changed to create a valid path from the top-left to the bottom-right corner of the grid.

Input:

 T 
 N M 
 grid[0][0] grid[0][1] ... grid[0][M-1] 
 ...
 grid[N-1][0] grid[N-1][1] ... grid[N-1][M-1] 

Output:

 Minimum number of direction changes to create the path for each test case. 

Example:

Input:

1 
 2 2 
 R D 
 L D 

Output:

0

Explanation:

The given grid allows a direct path from top-left to bottom-right following the directions without any changes.

Constraints:

• 1 ≤ T ≤ 10
• 1 ≤ N, M ≤ 100
• Each cell contains one of {'U', 'L', 'D', 'R'}.
• Time Limit: 1 second

Note:

You do not need to handle input/output. Implement the function and return the result.