I did the first Project Euler problem. Since the goal for an easy one like this was more about getting tool chain issues sorted out I went ahead and did it the brute force O(n) way. I had planned on working out the more efficient solution which should be O(1), but they actually discuss it in the explanation you get after reading it, so now I don’t know if I will or not.
Doing it the more efficient way would still let me play around with pointing a profiler at it or something to actually measure the difference, so maybe I still will. I definitely will for some problems, I just don’t know if I’ll bother with one this simple.
EDIT: Decided to go ahead and do the smarter version. Also found a bug in the brute force version while doing so and fixed it.
EDIT2: Removed link to github (and made repo private) because it is against the rules to reveal solutions.