Hello, in 2 days I am participating to a informatics olympiad and I thought it would be useful to know some algorithms.

There is no required knowledge of any programming language, so it's just about the logics behind programming and a few algorithms.

In fact I don't know many of them. The only one I could think of is Dijkstra's algorithm and the shunting yard algorithm.

But I am sure that they won't ask anything about the shunting yard algorithm and dijkstra seems very intresting.

Now my question is if you know a few algorithms which could be useful? I don't think they will ask anything about arithmetic stuff such as karatsuba and fourier(?) for multiplication and stuff.

Thanks in advance.