Merge Two Sorted Arrays Problem Statement

Given two sorted integer arrays ARR1 and ARR2 of size M and N, respectively, merge them into ARR1 as one sorted array. Assume that ARR1 has a size of M + N to hold all elements of ARR2.

Input:

The first line contains an integer T representing the number of test cases. Each test case contains: 
- Two space-separated integers M and N.
- A line with M integers followed by N zeros in ARR1.
- A line with N integers in ARR2.

Output:

For each test case, return the merged ARR1 as one sorted array.

Example:

Input:
ARR1 = [3, 6, 9, 0, 0]
ARR2 = [4, 10]
Output:
ARR1 = [3, 4, 6, 9, 10]

Constraints:

• 1 <= T <= 100
• 1 <= M, N <= 5000
• 1 <= ARR1[i], ARR2[i] <= 100000

Time Limit: 1 second

Note:

Ensure the function implementation handles the merging, output has already been managed.