## 區間合併
[影片](https://www.bilibili.com/video/BV1rw411Q7ic/?spm_id_from=333.337.search-card.all.click)
[洛谷P1496 火燒赤壁](https://www.luogu.com.cn/problem/P1496)
## 離散化
[離散化1](https://www.cnblogs.com/cytus/p/8933597.html)
[離散化2](https://www.luogu.com.cn/blog/5002-qwq/post-xue-xi-bi-ji-li-san-hua)
題目:
1.[洛谷P1955 [NOI2015] 程序自动分析](https://www.luogu.com.cn/problem/P1955)
這題要用到並查集
2.