want

2-SAT POJ3683

操作树

仙人掌 HDU3594

平衡树

916D 可持久化Trie

https://www.cnblogs.com/jszkc/p/7309468.html

http://www.cnblogs.com/joyouth/p/5604618.html

https://www.cnblogs.com/meowww/p/6485422.html
https://blog.csdn.net/clover_hxy/article/details/69397184
https://www.lydsy.com/JudgeOnline/problem.php?id=1016
https://www.cnblogs.com/zj75211/p/8039443.html