CF #261 div2 D. Pashmak and Parmida's problem （树状数组

Parmida is a clever girl and she wants to participate in Olympiads this year. Of course she wants her partner to be clever too (although he's not)! Parmida has prepared the following test problem for Pashmak. There is a sequence a that con

Parmida is a clever girl and she wants to participate in Olympiads this year. Of course she wants her partner to be clever too (although he's not)! Parmida has prepared the following test problem for Pashmak.

There is a sequence a that consists of n integers a₁,?a₂,?...,?a_n. Let's denote f(l,?r,?x) the number of indices k such that: l?≤?k?≤?r and a_k?=?x. His task is to calculate the number of pairs of indicies i,?j (1?≤?i?j?≤?n) such that f(1,?i,?a_i)?>?f(j,?n,?a_j).

Help Pashmak with the test.