> For the complete documentation index, see [llms.txt](https://feifeizheng.gitbook.io/leetcode/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://feifeizheng.gitbook.io/leetcode/master.md).

# Preface

## "If you can't explain it simply, you don't understand it well enough." – Albert Einstein

This book contains all the problems I have solved in [LeetCode](https://leetcode.com/).

All the explanation is based on Google Research, Baidu Research and self-understanding.

Solutions are written in Python.

See markdown version on [GitBook](https://feifeizheng.gitbook.io/leetcode/)