After your war, you will be able to see your code in comparison with your opponent's. If their solution was better than yours, you can learn from their code and next time adapt it into your code if you like it. It's a fantastic, fun way to learn among peers.
Often translated to another language, challenges have glitches and sometimes, correct solutions cannot pass tests. Challenge/translation approval process is too relaxed and stimulates quantity rather than quality.
Division 1 upper levels in Topcoder has problems which forces users to think about which is the correct algorithm to use to solve them. A lot of problems will also force developers to use multiple data structures and algorithms to find the solution.
Users can publish their solutions for different problems and other users can review the code and give their opinions on how they would have solved the problem. Sometimes, some of the most active users get their code reviewed by Guido Van Rossum (the creator of the Python language) himself.
GeeksForGeeks was founded to create a place for people who want to prepare for job interviews at big tech companies would have a place to prepare for these interviews. The most important challenges and problems get articles published daily on how to solve them with detailed instructions and expla...
The Codechef forums are not very active and they are the official way of interacting inside the Codechef community. Other than the forums, the only way of interacting with other members of the community is through the comment sections of different problems.
CareerCup was founded in 2005 and it has been popular for a lot of time. During this time users have been posting a lot of questions and challenges and as a result have created one of the largest databases of interview questions.