Find the Kth Largest in Two Sorted Arrays

You are given two arrays sorted in ascending order and an integer k. Return the kth largest element among all elements from both arrays combined.

Count duplicates as separate elements.

Example:

• a = [0, 1, 4, 5, 6, 7, 8, 10, 13]
• b = [1, 3, 4, 5, 8, 9, 11, 12]
• k = 3

The combined elements in descending order begin with 13, 12, 11, 10, ..., so the answer is 11.

Find the Kth Largest in Two Sorted Arrays

You are given two arrays a and b, both sorted in ascending order, and an integer k. Return the kth largest element among all elements from both arrays combined.

Duplicates count as separate elements. For example, if the combined sorted order is [9, 8, 8, 7], then the 2nd largest element is 8 and the 3rd largest element is also 8.

Try to use the fact that the arrays are already sorted.

Constraints

• 0 <= len(a), len(b) <= 200000
• 1 <= k <= len(a) + len(b)
• -1000000000 <= a[i], b[i] <= 1000000000
• Both arrays are sorted in non-decreasing order

Hints

1. The largest remaining element must always be at the end of one of the two arrays.
2. This is similar to the merge step of merge sort, but done from right to left and stopped after taking k elements.