Saka-Noa

摘要： 定义 $t(p_1 \to p_2) = z_{0}\times k^{0}+z_{1}\times k^{1} + \cdots + z_{l-1} \times k^{l-1}$，$f(r) = [r = x]$ 则答案为$$\sum_{p_1 \in n}\sum_{p_2 \in n} \s 阅读全文