Hello fellow anons, this thread is dedicated to the pursuit of competitive problem solving as a mind sport and hobby.
Resources:
Math/general:
>The Art and Craft of Problem Solving (Paul Zeit)
>How to solve it (G. Polya)
Competitive programming:
>Competitive programmer's handbook (Antti Laaksonen)
>List programming problems to solve
a2oj
>Codeforces
Physics:
>Olympiad physics training material: (none as of yet)
Today's problem: Mexico 2019 Olympiad Problem 4
A list of positive integers is called good if the maximum element of the list appears exactly once. A sublist is a list formed by one or more consecutive elements of a list. For example, the list 10,34,34,22,30,22 the sublist 22,30,22 is good and 10,34,34,22 is not. A list is very good if all its sublists are good. Find the minimum value of k such that there exists a very good list of length 2019 with k different values on it.
Remember to show your work. Suggestions welcome.