Problems: https://cses.fi/problemset/list

Here's my progress so far (I cut out the last few rows that correspond to addional problems):

For reference here's a little boy doing all (all the the problem set has changed somewhat) but "advanced techniques" and "additional problems" in 12 hours: https://www.youtube.com/watch?v=dZ_6MS14Mg4

I will not look up any answers, but I might study well-known techniques like variations on segments trees or computatonal geometry techniques.

I will not bet in this market.