# Sliding Window 滑窗

讲真真的得好好想想这一类问题。

一般有两种选择，先从窗口中移除元素，再加入新元素；另一种就是先加入元素再移除一些元素。 有的时候两者都可以。 还有一种分法，一种是固定长度的窗口，一种是不固定长度的窗口。 这个问题想好了，题目就能写好。

* [076: Minimum-Window-Substring](https://leetcode.com/problems/minimum-window-substring/)
* [003: Longest-Substring-Without-Repeating-Characters](https://leetcode.com/problems/longest-substring-without-repeating-characters/)
* [030: Substring-with-Concatenation-of-All-Words](https://leetcode.com/problems/substring-with-concatenation-of-all-words/)
* [159: Longest-Substring-with-At-Most-Two-Distinct-Characters](https://leetcode.com/problems/longest-substring-with-at-most-two-distinct-characters/)
* [424: Longest-Repeating-Character-Replacement](https://leetcode.com/problems/longest-repeating-character-replacement/) 有点难度啊

## 固定长度的滑窗

* [438: Find-All-Anagrams-in-a-String](https://leetcode.com/problems/find-all-anagrams-in-a-string/)
