Problem discussion: Facebook Hacker Cup 2015 Round 1 - Homework
It's been a long time since I last wrote on this blog and a lot has happened since then. The most important of all is that my personal website is up at anirudhrb.com and consequently this blog can now be accessed at blog.anirudhrb.com . Also, you can now reach through email at mail@anirudhrb.com . Let's get down to business now. The online part of Facebook Hacker Cup 2015 concluded recently and the top 25 contestants have been selected to compete in the onsite finals. The problem I am writing about in this post appeared in the Round 1 (there were 3 rounds). The title of the problem is "Homework" and here is the abridged statement: Given three integers \(A\), \(B\) and \(K\), find the number of integers in range \(\big[A, B\big] \) that have a "primacity" of \(K\). Primacity of a number \(N\) is defined as the number of distinct prime factors of \(N\). You have to process \(T\) such queries. The constraints are as follows: \(2 \le A \le B \le 10^...