问题 D: Data Generation

内存限制：256 MB 时间限制：1 S 标准输入输出

题目类型：传统评测方式：文本比较上传者：

提交：1 通过：1

Yoshinow2001 is making data for his problem. He wants to generate a random permutation of

{0, \dots, n - 1}

, so he used the following algorithm:

Here, we can assume that the function

r an d () mod n

is able to generate integer randomly in the set

{0, \dots, n - 1}

with equal probability.

Now Yoshinow2001 is concerned that this algorithm is not random enough ------ after all, if you want to randomize a permutation, the expected number of elements for $a_{i} \neq = i$ should be $n - 1$ . So he wants to ask what the mathematical expectation of the final $an s$ is.

The first line of input is a positive integer $T (1 \leq T \leq 1 0^5)$ representing the number of data cases.

For each cases consists of a single line of two integers $n, m$ , separated by a space. Where $1 \leq n \leq 1 0^18$ , $0 \leq m \leq 1 0^18$ , ensure that $n$ is not a multiple of $998244353$ .

For each cases, output a line with a positive integer representing the answer

mod 998244353

0
0
1

问题 D: Data Generation

题目描述

输入格式

输出格式

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问题 D: Data Generation

题目描述

输入格式

输出格式

输入样例 复制

输出样例 复制

输入样例复制

输出样例复制