高维前缀和及其同构品
高维前缀和给一个 intrada 性质的问题:求 $\displaystyle F[mask] = \sum_{i \subseteq mask} A[i]$这个形式看起来会很像一个 and-c...
In mathematics you don't understand things, you just get used to them.
In mathematics you don't understand things, you just get used to them.