Algorithm-finding kth next element in an array

Question

I couldn\'t solve a question can you please help?

For i=1 to i=n/2, if A[i]<=A[2i] and A[i]<=A[2i+1] A is called as a \"bst\" 

What\

Answer 1

There are two methods:

1. O(k ln(n)) time complexity.
2. O(k ln(k)) time complexity + O(K) space complexity.