An entire post covering both the theoretical part and the implementation is going to take too long, for this reason I’m splitting the material in two parts: A post with some theory introduction, and one post which will be focused on implementation details. The algorithm I would like to show you is the Ukkonen method for […]

# engineering

## 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 […]

- C++
- ...

## IO Stream performance.

Many of the competitive programming portals available on the web advice –for certain problems involving huge input reading or output printing– the user to avoid cin/cout in spite of printf/scanf: As input/output can reach huge size it is recommended to use fast input/output methods: for example, prefer to use scanf/printf instead of cin/cout in C++, prefer to use […]