some algorithms #esay algorithms
| 文件名 | 描述 |
|---|---|
| delete node | 删除某节点 |
| Contains duplicate | 是否数组包含重复数字，使用hashSet |
[Stack and Queue](https://github.com/wangwanlin/algorithms/blob/master/easy/Stack%20and%20Queue) | 栈和队列以及用栈实现队列
[Remove Duplicates from Sorted Array](https://github.com/wangwanlin/algorithms/blob/master/easy/%20Remove%20Duplicates%20from%20Sorted%20Array) | 删除重复数字，两个指针
[power of three.docx](https://github.com/wangwanlin/algorithms/blob/master/easy/power%20of%20three.docx) | 是否是三的指数
[rotate array](https://github.com/wangwanlin/algorithms/blob/master/easy/rotate%20array) | 数组元素后移，k %= a.length，k要先取下余
#medium algorithms
| 文件名 | 描述 |
|---|---|
| range sum query | 求数组和effectively |