Problems are interesting and challenging.

However, I performed badly :(

Good contest.

It lets my brain spin fast :)

How can you come up with the goated solution for B ?

The tests of D are sort of weak, but I'm not sure if it's possible to make properly strong ones. My submission link gets AC, but it fails on the test

1
9 100
3 44 66 83 84 88 94 94 98
35 53 62 64 65 68 70 80 97

giving 81 instead of optimal (verified with bruteforce) 56. I noticed by stresstesting on random inputs that adding more repetitions of The Loop (look at the submission, you'll see which loop I mean) makes it much, much harder to still find a failing small test.

F is a great problem, but I'm not good at greedy, so I simply took the solution of A, and did some standard transformation to make it F. I think it wasn't intended but it just worked!

Hi, can anyone help me show me what im doing wrong here for problem A?

Code

My idea is that I try to prioritize getting Div1 contests and then I keep track of how many of them I can change to div2 contests. If there are enough ways to change, then I try to change it so that there is an equal number of both contests. I think the idea is quite similar to the idea in the editorial. Furthermore, after generating random testcases and comparing with an AC solution, I still haven't found any countercases.

The link to Code in the solution of prob B contains some incorrect dollar signs.