Codechef
LeetCode
HackerRank
Coderbyte
AlgoExpert.io
Codewars
CodeForces
Interview Cake
Teachable
Clever
PowerSchool
Claroline
Canvas by Instructure
LanSchool
Treehouse
Fedena
CodeChef is a not-for-profit educational initiative started by Directi more than a decade ago. We started with a dream of seeing an Indian team winning a gold medal at the ACM ICPC World Finals. In its quest for the same, CodeChef has built a self-driven community of the world's best programmers. Today more than 1.3 million competitive programmers from 180+ countries learn from CodeChef. CodeChef has been hosting monthly programming contests regularly for 10 years now. Its platform has assessed 92 million+ code submissions to date, and over 30000 organizations are being impacted by CodeCheffers worldwide. It also organizes SnackDown - one of the world's largest global programming competition whose last edition drew participation from 140+ countries. Since 2017, CodeChef has started providing India's only industry-ready certification in Data Structures and Algorithms, and 1800+ programmers have been certified under the same.
Codechef TeachableBased on our record, Codechef seems to be more popular. It has been mentiond 7 times since March 2021. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.
Have you heard of codeforces.com, atcoder.jp, codechef.com, etc? Source: 6 months ago
Leetcode is good to learn basic algorithms because problem statements are usually straightforward. Competitive programming has much wider range of problems. Most popular sites for cp are codeforces.com , atcoder.jp, codechef.com . Source: 6 months ago
Learn Java with hands-on experience. I personally used codingbat.com a lot, but I've heard good things about codechef.com, which appears to even have a competitive option. Source: about 1 year ago
For practicing algorithms, use any of the freely available websites like https://hackerrank.com https://codechef.com https://projecteuler.net A structured set of practice problems are available at https://www.interviewbit.com/courses/programming/ Avoid https://geeksforgeeks.org because it has a ton of material but very poor quality control. Source: almost 2 years ago
These all have sample problems to solve Hackerrank.com edabit.com codewars.com codechef.com and there are tons more. Best of luck to you. I am at about the same level myself. I really like these sites. Source: over 2 years ago
LeetCode - Practice and level up your development skills and prepare for technical interviews.
Clever - syncing between education applications for K-12 schools
HackerRank - HackerRank is a platform that allows companies to conduct interviews remotely to hire developers and for technical assessment purposes.
PowerSchool - PowerSchool provides a K-12 education technology platform for operations, classroom, student growth, and family engagement.
Coderbyte - Coderbyte is a place built for anyone to practice and perfect their programming skills.
Claroline - Claroline is a collaborative eLearning and eWorking platform.