I am unable to understand the O(n log n) algorithm. I've found many examples, but there are too difficult for me. Could somebody explain it in simple words ? I saw that a lot of users use lower_bound, but I don't see why it works.
I know that there'll be answers like google it etc, but I've already spent many hours and I didn't find anything useful.
I just found this one. It's clearly explained here. http://www.geeksforgeeks.org/longest-monotonically-increasing-subsequence-size-n-log-n/