加练题单

加练加练 T3题目的trick很巧妙，适合多次回头看 [#1并查集](https://www.luogu.com.cn/training/3065#problems) [#2树状数组](https://www.luogu.com.cn/training/3079#information) [#3线段树1](https://www.luogu.com.cn/training/1124) [#4线段树2](https://www.luogu.com.cn/training/44326#problems) [#5堆与树状数组](https://www.luogu.com.cn/training/205#problems) [#6块状数组，块状链表，分块的简单题及难题](https://www.luogu.com.cn/training/5028#problems) [#7kb的数列分块&整除分块入门题单](https://www.luogu.com.cn/training/11849#problems) [#8【提高】二叉堆/优先队列应用](https://www.luogu.com.cn/training/3958#information)