AtCoder Grand Contest 060
D
Same Descent Set
AtCoder
⌀ 3394
原题
← CE →
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Problem Statement

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Find the number of pairs $(P,Q)=((P_1,P_2,\cdots,P_N),(Q_1,Q_2,\cdots,Q_N))$ of permutations of $(1,2,\cdots,N)$ that satisfy the following condition, modulo $998244353$.

翻译中…
  • For every $i$ ($1 \leq i \leq N-1$), one of the two conditions below holds.
  • $P_i < P_{i+1}$ and $Q_i < Q_{i+1}$.
    • $P_i > P_{i+1}$ and $Q_i > Q_{i+1}$.
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Constraints

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  • $2 \leq N \leq 2 \times 10^5$
  • All numbers in the input are integers.
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Input

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The input is given from Standard Input in the following format:

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N

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Output

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Print the answer.

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样例

Input #1
2
Output #1
2
Two pairs, $(P,Q)=((1,2),(1,2))$ and $(P,Q)=((2,1),(2,1))$, satisfy the condition.
Input #2
3
Output #2
10
Input #3
4
Output #3
88
Input #4
10
Output #4
286574791
题目信息
题号
agc060_d
时间限制
6 s
内存限制
1024 MB

题面与样例版权归 AtCoder 及出题人所有;中文翻译由 AI 生成(CI 管线),如有出入请以原文为准。