Problem: Integers have friends.

After seeing the tutorial of this problem, I learnt about the sparse table. The tutorial though provides the method which is sparse table construction and then using binary search, I could not completely understand it. The comment section was pretty helpful but now the older comment section has been deleted. Can someone please explain what they have done( preferably an approach using sparse table because I have spent a lot of time learning it.)

If possible, please explain it in a beginner-friendly manner as I have never used a sparse table till now. It would really be helpful to me...

Hey everyone.Hope u all are doing fine.I need a little help as I am stuck at one particular rating.I am generally able to solve problems upto 1300 level although the math ones do take time.I have knowledge about basic data structures such as array, map,vector,string and set and use a bit of C++ stl but I do not have any idea about any higher data structure or algorithm such as graph tree or dp. I just know their names as I frequently see their name in the editorial:) Can someone tell me what to learn now and then how to proceed further.I really want to improve but am just unable to solve the 1400 tag questions.

Here is my solution. I could not understand the editorial code but tried to follow a simple method.Don't know where its going wrong... https://codeforces.net/contest/1157/submission/88502505