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_\

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.

Druid

Druid是一个由MetaMarket Inc主导的开源项目, 用来实现实时分析大规模数据的平台. Druid使用Apache V2许可.

目标

Apache Kylin希望在3.0加入低延迟的数据查询特性, 需要做技术积累和想法验证.

• 20180928 -> 20181007 学习Druid的概念/架构/使用

• 20181008 -> 20181031 学习Druid如何摄入数据, 保存数据, 查询数据

1. 什么是Druid? 简介、概况、架构图
2. 什么是Kylin/Kyligence? 简介、概况、架构图
3. 产品各自重点特性Feature highl