Summary for the week.

This was a very long week! Most of my free time I was at the gym or on my combinatorics book learning fancy details about the pigeonhole principle, which is very simple but with large implications in problem solving. The pigeonhole principle basically say that if you want to put three pigeon in two holes,… Continue reading Summary for the week.

Subsequences and Fenwick tree’s

Let’s say that we have a sequence A of 1<=n<=10^5 elements, and that this sequence may or may not be ordered but all the numbers {1…n} are present exactly once. And now given 1<=k<=10, you’re asked to find all the increasing sub-sequences of A with exactly k+1 elements. This is a problem I get from a competitive programming… Continue reading Subsequences and Fenwick tree’s