The contest is over. You can submit the three problems (lcs, modinv, sssp) on the main judge.

FatalEagle has prepared 3 classic problems for you to solve in any 3 hour window. You might not need the full 3 hours, and that's fine. Internet access is allowed, but please don't just copy paste a solution from the Internet. The goal is for you to learn some classic algorithms that may be of use in contests. A Wikipedia article has been provided with each problem.

The timer will start running as soon as you click "Join Contest". If you would like to restart your timer, post in the comments with a valid reason.