Warning: this repo contains spoliers - do not investigate further unless you have attempted to solve the challenges yourself first!
From the Project Euler mainpage:
Project Euler is a series of challenging mathematical / computer programming problems that will require more than just mathematical insights to solve. Although mathematics will help you arrive at elegant and efficient methods, the use of a computer and programming skills will be required to solve most problems.
In the Project Euler archives are the problems themselves, and each folder in this repo will contain code for determining the solutions.