I have tried to make video tutorial for binary search and its application to solve Problem D of Codeforces round 635, hoping to help people understand the problem and what was my approach for the same. Please do like the video and do subscribe for more such content.
Tutorial(Par1) : Binary Search tutorial
Tutorial (Part2: Application to solve problem): Codeforces Round #635 (Div. 2) Problem D: Binary Search Tutorial (Part 2)