エクサウィザーズプログラミングコンテスト2021(AtCoder Beginner Contest 222)
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Problem Statement
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For a positive integer $N$, a rooted binary tree that satisfies the following conditions is said to be a beautiful binary tree of degree $N$.
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- Each vertex has
$0$or$1$written on it. - Each vertex that is a leaf has
$1$written on it. - It is possible to do the following operation at most
$N-1$times so that the root has$N$written on it and the other vertices have$0$written on them. - Choose vertices
$u$and$v$, where$v$must be a child of$u$or a child of "a child of$u$." Let$a_u \gets a_u + a_v, a_v \gets 0$, where$a_u$and$a_v$are the numbers written on$u$and$v$, respectively.
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Given $N$, find the number, modulo $998244353$, of beautiful binary trees of degree $N$.
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Constraints
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$1 \leq N \leq 10^7$- 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
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Output
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Print the answer.
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样例
Input #1
1
Output #1
1
The only binary tree that satisfies the condition is a tree with one vertex whose root has $1$ written on it.
Input #2
2
Output #2
6
The binary trees that satisfy the condition are the six trees shown below.

Input #3
222
Output #3
987355927
Input #4
222222
Output #4
675337738
题目信息
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。