Project Euler #912: Where are the Odds?

I have spent a little time with Project Euler. Is it very popular with those here at HN?

It’s my game plan for keeping my brain active in retirement. Been heavily involved for the past 7 years. Been at the 100% solved level since summer 2023, though I’m back to one away the past couple weeks - PE910 is _hard_

Wow. The idea of getting to 100% on PE is almost incomprehensible to me. I've solved basically none outside the first couple pages.

What was your strategy like? How much math background do you have?

I've got a bachelor's in math, but that's 40+ years ago. I had intended to go on for a PhD in math, but fell into computers instead - programming was easier and way more lucrative, even in the early 80s. Once I was retired and found my way to Project Euler, it became an obsession, tickling that desire to go deeper into math that I had in my college days.

I attacked roughly the first 250 problems in order. The early problems build on each other to introduce new topics. I also got good at figuring out the right search term to find some random paper in number theory, combinatorics, probability, whatever.

Later problems introduced new, more niche areas, like chromatic polynomials and impartial & partisan game theory. But by then, I found it much easier to figure out what part of math a problem was based on and how to find relevant literature.

It helps to be really really stubborn, and to have the patience to let a problem stew in my brain, sometimes for weeks at a time. That seems to help lead to that Eureka moment.