Question
给一个数组a[n]，令s[i]为a[i+1..n-1]中比a[i]大的数的数量。
求最大的s[i]。要求O(nlogn)
Solution
This is very similar question to [Google] Form a Queue Given Heights. The idea is to insert elements into BST and count number of larger elements.
Naitive solution can be reached with a list.