This repository contains problem solutions, notes, and optimizations across multiple languages. It's intended as a study and reference resource for practicing algorithms and data structures.
Recommended sites (frequently used)
- https://leetcode.com (LeetCode - International)
- https://leetcode.cn (LeetCode - China)
- https://adventofcode.com
- https://www.lintcode.com
- https://www.luogu.com.cn
- https://www.nowcoder.com
- https://www.patest.cn
- https://www.pramp.com
- http://www.pythonchallenge.com
- https://www.topcoder.com
- https://codeforces.com
Favorite authors / channels
- https://space.bilibili.com/206214
- https://leetcode.cn/u/endlesscheng/
- https://zerotrac.github.io/leetcode_problem_rating/#/
Possibly changed or deprecated links
- http://poj.org — legacy online judge; intermittent availability
- https://foobar.withgoogle.com/ — Google Foobar (restricted access)
- https://binarysearch.com — may have changed domain or redirect
- https://www.leetcode-cn.com — unofficial / defunct domain
- https://neetcode.io — may have changed domain or redirect
Languages & content
- Solutions and notes available in: Python2/3, C, C++, Java, Go, C#, JavaScript, Shell, Rust, SQL, etc.
Contributing
- Pull requests are welcome. For major changes, open an issue first to discuss.
- Report broken links or suggest replacements via Issues.