title: how to determine if the kth largest element of the heap is greater than x
body: <p>Consider a binary heap containing n
  numbers (the root stores the greatest number). You are given a
  positive integer k &lt; n and a number x. You have to determine whether
  the kth largest element of the heap is greater than x or not. Your
  algorithm must take O(k) time. You may use O(k) extra storage</p>