Minimum Moves to Collect All Keys

Given an 'N' x 'M' grid, find the minimum number of moves required to collect all keys when starting at a specified point. Each move allows you to travel to an adjacent cell (up, down, left, right). The grid contains walls, locks, keys, and a starting point, and you must adhere to specific movement rules.

Example:

Input:

GRID = [["@.aA"], [".B#."], ["...b"]]

Output:

5

Explanation:

Starting from '@', collect all keys in 5 moves without being hindered by locks if you have their respective keys.

Input:

The first line contains an integer 'T', the number of test cases.
For each test case:
- An integer 'N', the number of rows in the grid.
- Followed by 'N' strings, each string representing a row of the grid.

Output:

For each test case, output the minimum number of moves to collect all keys, or -1 if impossible.

Constraints:

• 1 <= T <= 10
• 1 <= N <= 100
• 1 <= M <= 100
• GRID[i][j] is either an English letter, '.', '#', or '@'.
• Each key is unique and has a matching lock.
• Alphabets for keys and locks follow English alphabetical order.
• The number of keys ranges from 1 to 6.
• Time Limit: 1 second

Note:

Implementation should only return results and not handle print logic.