leetcode solutions for coding interviews

Reference links:

1. LeetCode: https://leetcode.com/
2. LeetCode China: https://leetcode-cn.com/
3. wisdompeak's LeetCode Repo: https://github.com/wisdompeak/LeetCode.git
4. Leetcode's Solution Repo: https://github.com/lzl124631x/LeetCode
5. System Design Primer: https://github.com/donnemartin/system-design-primer.git