• We have BFS and DFS images in both Breadth First Traversal and Depth First Traversal. We should have illustrations in the respective sections.

一个班级60%喜欢足球，70%喜欢篮球，80%喜欢排球，问：三种球都喜欢占比最大可能有多少，最小可能有多少？即求三种球都喜欢的比例范围

🚀 Feature Proposal

Adding leading zero in the question number will be an awesome feature for file explorer to sort files by the name.

Given a blacklist B containing unique integers from [0, N), write a function to return a uniform random integer from [0, N) which is NOT in B.

Optimize it such that it minimizes the call to system’s Math.random().

Note:

1. 1 <= N <= 1000000000
2. 0 <= B.length < min(100000, N)
3. [0, N) does NOT include N. See [interval notation](https://en.wikipedia.org/wiki/Interval_\

Add new sections by GitbookIO editor is quite simple, but sometimes you may forget to add sections in SUMMARY.md.

It is easy to parse the title of source .md files and add it to the appropriate chapter position. I will implement this feature with Python.

It'll be good to add an introduction into the readme for the basic information of the repo, such as where are the problems coming from, how do you pick problems into this repo, etc.