Free algorithm tools or service for developers
A collection of free algorithm app, tools or service for developers
![Logo thumbnail for Codeforces](https://codeforces.org/s/0/apple-icon-180x180.png)
Codeforces
Codeforces. Programming competitions and contests, programming community
Tags: algorithm, learning-resource, code-practice
Free Offer:
free problem set, free course
![Logo thumbnail for Project Euler](https://projecteuler.net/images/clipart/euler_portrait.png)
Project Euler
Project Euler is a series of challenging mathematical/computer programming problems that will require more than just mathematical insights to solve
Tags: learning-resource, code-practice, algorithm