ICPC2019 南京. E. Observation(思路)
令$f(d)$a56爆大奖在线娱乐空间中到原点距离为$d$的整点个数，给定$L,R,k,p$，求
$$\sum_{d=L}^Rf(d)\ \mathbb{xor}\ k\mod p$$
$L,R\leq 10^{13},R-L+1\leq 10^6$。
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很久以前的奇怪但现在依旧成立的签名
attack is our red sun $$\color{red}{\boxed{\color{red}{attack\ is\ our\ red\ sun}}}$$ ------------------------------------------------------------------------------------------------------------------------
很久以前的奇怪但现在依旧成立的签名
attack is our red sun $$\color{red}{\boxed{\color{red}{attack\ is\ our\ red\ sun}}}$$ ------------------------------------------------------------------------------------------------------------------------
