HackerRank is great. I agree with @bko. I would also like to point out a few books that I read in college that helped me out too. Cracking the Coding Interview is a great book that explains the most common algorithms job interviews will ask. Reading is my favorite way of learning.<p><a href="http:&#x2F;&#x2F;www.amazon.com&#x2F;Cracking-Coding-Interview-Programming-Questions&#x2F;dp&#x2F;098478280X" rel="nofollow">http:&#x2F;&#x2F;www.amazon.com&#x2F;Cracking-Coding-Interview-Programming-...</a>