Project Euler Offline
github.com
github.com
I clicked the link thinking it meant something different, that Project Euler's website (projecteuler.net) itself was down. But it is working fine, at least at the moment. You can all relax.
Project Euler was a cool idea, but it always feels to me like the worst of Leetcode interviews and the worst of riddle interviews combined - it's not that your solution will be suboptimal, it's that you will not be able to solve many of the problems before the heat death of the universe unless you know this one weird trick.
Some problems are just fun to work out mostly through code, like Poker Hands [1] or Monopoly [2], and other more geometric ones like Magic 5-gon ring [3] or Hexagonal tile differences [4] are nice to just reason about on paper. These don't really require much specific knowledge. For problems requiring more knowledge to find useful tricks to solve the problem, I'll often load some related Wikipedia pages I can study on a flight or train ride.
[1] https://projecteuler.net/problem=54
[2] https://projecteuler.net/problem=84