I was solving a problem on SPOJ which says to count inversions. It can be solved using BIT or Merge Sort algorithm. I searched the topic on the internet, I found a page on Geeksforgeeks with exactly the same problem. So I try to understand it, but after a while I could not get much of it. So I copied those functions and used it directly in my solution. But I started feeling guilty. I am interested to know how you guys learn an algorithm. This is my first blog post, so please ignore if I made any mistakes and help me. Thank you. ^_^