Calculating

ID: 2857

远端评测题

1000ms

128MiB

尝试: 0

已通过: 0

难度: 7

上传者:

root

标签>

数学

洛谷原创

O2优化

Description

If the prime factorization of $x$ is $x=p_1^{k_1}p_2^{k_2}\cdots p_n^{k_n}$ , define $f(x)=(k_1+1)(k_2+1)\cdots (k_n+1)$ . Compute $\sum_{i=l}^r f(i)$ modulo $998\,244\,353$ .

Input Format

The input contains a single line with two integers, representing $l$ and $r$ .

Output Format

Output a single integer on one line representing the answer.

2 4

Hint

Constraints and Conventions

Test point ID	$l$	$r$	$r-l$
$1\sim 3$	$1\le l\le 10$	$1\le r\le 10$	$r-l=0$
$4\sim 7$	$1\le l\le 50$	$1\le r\le 50$	$r-l=0$
$8\sim 10$	$1\le l\le 100$	$1\le r\le 100$	$r-l<50$
$11\sim 16$	$1\le l\le 500$	$1\le r\le 500$	No special restriction
$17\sim 25$	$1\le l \le 10^3$	$1\le r \le 10^3$	No special restriction
$26\sim 30$	$1\le l \le 5\times 10^3$	$1\le r \le 5\times 10^3$	$r-l<100$
$31\sim 40$	$1\le l \le 10^4$	$1\le r \le 10^4$	No special restriction
$41\sim 60$	$1\le l \le 10^7$	$1\le r \le 10^7$
$61\sim 70$	$1\le l \le 10^9$	$1\le r \le 10^9$
$71\sim 90$	$1\le l \le 10^{12}$	$1\le r \le 10^{12}$
$91\sim 95$	$1\le l \le 10^{13}$	$1\le r \le 10^{13}$
$96\sim 97$	$1\le l \le 2\times 10^{13}$	$1\le r \le 2\times 10^{13}$	$r-l<10^{13}$
$98\sim 99$	$1\le l \le 10^{13}$	$1\le r \le 10^{14}$	$r-l>9\times 10^{13}$
$100$	$1\le l \le 10^{14}$	$1\le r \le 1.6\times 10^{14}$	$r-l>10^{14}$

Translated by ChatGPT 5

#P3935. Calculating

Description

Input Format

Output Format

Hint

Constraints and Conventions

还没有账户？

登录