Problem statement: Find \$kth\$ largest element in the union of two sorted array.
My introduction of the algorithm I spent a few hours to review two algorithms, Leetcode 4:Median of Two Sorted Arrays and Leetcode 215:Kth Largest Element in an Array together since median is a special case of kth element problem, and also read the article to talk about the kth largest element in the union of two sorted array, 3 solutions: 1:The trivial way, \$O(m+n)\$; 2: A better way, O(k); 3: The best solution, but non-trivial, O(lg m + lg n).
So, I decided to practice the algorithm "Find kth largest element in the union of two sorted array" (similar to Leetcode 4 and 215, but with some difference.), using binary search non-trivial one, C# Source code. Please help me to review the code.