1.二维偏序（树状数组）| 后缀
https://blog.csdn.net/xp731574722/article/details/78354178
树状数组做法 https://blog.csdn.net/qq_35914587/article/details/79061277
https://blog.csdn.net/Irish_Moonshine/article/details/80578303 （这里的树状数组实现的其实是求
后缀和的功能）
2 三维偏序
https://blog.csdn.net/reverie_mjp/article/details/52462651
4 二维树状数组讲解
https://blog.csdn.net/qq_36778821/article/details/77387691
https://blog.csdn.net/weixin_41156591/article/details/81150855
5 另一道二维偏序【BZOJ1109】[POI2007]堆积木Klo
6 多维偏序 https://blog.csdn.net/jtjy568805874/article/details/50638665
7 有关二维树状数组的题目 https://blog.csdn.net/sky_j123/article/details/32913065
8 离散化+树状数组 https://blog.csdn.net/zP1nG/article/details/78016228

9 https://blog.csdn.net/soul_97/article/details/80710375
10 dp https://blog.csdn.net/xp731574722/article/details/76726305