UVa Online Judge
Here you will find hundreds of problems. They are like the ones used during programming contests. You can submit your solutions in a variety of languages including JAVA, Python 3.5, C++.
What is the largest prime factor of the number 600851475143?
- If problems like this look like a fun way to apply your programming knowledge, Project Euler is a great way to start. Once you have solved a problem, you gain access to the forum page for that question. Project Euler is free to use, and is one of that largest communities of programmers.
- Because project Euler does’t require you to submit source code, you can program in any language you choose to!
- get started website problems archives
Codechef is a global programming community that fosters learning and friendly competition, built on top of the world’s largest competitive programming platform. CodeChef was created as a platform to help programmers make it big in the world of algorithms, computer programming and programming contests. You can submit your solutions in a variety of languages including JAVA, Python 3.5, C++.
USA Computing Olympiad
Sphere Online Judge (SPOJ)
SPOJ – Sphere Online Judge – is a problemset archive, online judge and contest hosting service accepting solutions in many languages. SPOJ has over 315000 registered users and over 20000 problems.
Master the Mainframe
- IBM Master the Mainframe contests are hosted around the world, bringing exciting, enterprise computing challenges to students in every corner of the globe. These contests allow students to take charge of a world-class computing platform and showcase their talents, while earning great prizes and gaining sought-after enterprise computing skills
- Every year the United States contest is September through December