UNICORNプログラミングコンテスト2021(AtCoder Beginner Contest 225)
H
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原题
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Problem Statement

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There are $N$ chairs arranged in a row, called Chair $1$, Chair $2$, $\ldots$, Chair $N$. A chair seats only one person.

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$M$ people will sit on $M$ of these chairs. Here, let us define the score as follows:

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$\displaystyle \prod_{i=1}^{M-1} (B_{i+1} - B_i)$, where $B=(B_1,B_2,\ldots,B_M)$ is the sorted list of the indices of the chairs the people sit on.

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Person $i$ $(1 \leq i \leq K)$ is already sitting on Chair $A_i$. There are ${} _ {N-K} \mathrm{P} _ {M-K}$ ways for the other $M-K$ people to take seats. Find the sum of the scores for all of these ways.

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Since this sum may be enormous, compute it modulo $998244353$.

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Constraints

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  • $2 \leq N \leq 2 \times 10^5$
  • $2 \leq M \leq N$
  • $0 \leq K \leq M$
  • $1 \leq A_1 \lt A_2 \lt \ldots \lt A_K \leq N$
  • All values in input are integers.
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Input

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Input is given from Standard Input in the following format:

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N M K
A_1 A_2 \ldots A_K

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Output

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Print the answer.

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样例

Input #1
5 3 2
1 3
Output #1
7
If Person $3$ sits on Chair $2$, the score will be $(2-1) \times (3-2)=1 \times 1 = 1$. If Person $3$ sits on Chair $4$, the score will be $(3-1) \times (4-3)=2 \times 1 = 2$. If Person $3$ sits on Chair $5$, the score will be $(3-1) \times (5-3)=2 \times 2 = 4$. The answer is $1+2+4=7$.
Input #2
6 6 1
4
Output #2
120
The score for every way of sitting will be $1$. There are ${} _ {5} \mathrm{P} _ {5} = 120$ ways of sitting, so the answer is $120$.
Input #3
99 10 3
10 50 90
Output #3
761621047
题目信息
题号
abc225_h
时间限制
2 s
内存限制
1024 MB

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