Merge Sorted Array (LeetCode 88): merge two sorted arrays in place.
Asked in the phone screen stage. Easy LeetCode question asked first.
Implement merge(nums1, m, nums2, n). nums1 contains m sorted values followed by n empty buffer positions, and nums2 contains n sorted values. Modify nums1 in place so it contains all m + n values in nondecreasing order, then return nums1.
def merge(nums1, m, nums2, n):