Merge Sorted Array

You are given two integer arrays `nums1` and `nums2`, sorted in **non-decreasing order**, and two integers `m` and `n`, representing the number of elements in `nums1` and `nums2` respectively. **Merge** `nums2` into `nums1` as one sorted array **in-place**. The final sorted array should not be returned by the function, but instead be stored inside the array `nums1`. To accommodate this, `nums1` has a length of `m + n`, where the first `m` elements denote the elements that should be merged, and the last `n` elements are set to `0` and should be ignored. `nums2` has a length of `n`. > **Note for this platform:** The method returns the modified `nums1` for testability. **Example 1:** ``` Input: nums1 = [1,2,3,0,0,0], m = 3, nums2 = [2,5,6], n = 3 Output: [1, 2, 2, 3, 5, 6] ``` **Example 2:** ``` Input: nums1 = [1], m = 1, nums2 = [], n = 0 Output: [1] ``` **Example 3:** ``` Input: nums1 = [0], m = 0, nums2 = [1], n = 1 Output: [1] ```