Median-Level Array Manipulation

WePay's reporting tools receive transaction amounts from two already sorted sources. Given two sorted integer arrays, return the median of all values while avoiding unnecessary storage for a merged array.

Use the standard median definition: if the combined length is odd, return the middle value; if it is even, return the average of the two middle values.

Formal Specification

Implement median_two_sorted(nums1, nums2).

• Input: Two nondecreasing arrays of integers, nums1 and nums2.
• Output: A number representing the median. Return an integer when the median is integral, otherwise return a floating-point value.
• The input arrays may have different lengths, and either array may be empty.
• At least one array contains an element.