Codeforces Round 563 (Div. 2)
E
Ehab and the Expected GCD Problem
Codeforces
2500
原题
← DF →
翻译中…

Let's define a function $f(p)$ on a permutation $p$ as follows. Let $g_i$ be the greatest common divisor (GCD) of elements $p_1$, $p_2$, ..., $p_i$ (in other words, it is the GCD of the prefix of length $i$). Then $f(p)$ is the number of distinct elements among $g_1$, $g_2$, ..., $g_n$.

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Let $f_{max}(n)$ be the maximum value of $f(p)$ among all permutations $p$ of integers $1$, $2$, ..., $n$.

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Given an integers $n$, count the number of permutations $p$ of integers $1$, $2$, ..., $n$, such that $f(p)$ is equal to $f_{max}(n)$. Since the answer may be large, print the remainder of its division by $1000\,000\,007 = 10^9 + 7$.

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Input

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The only line contains the integer $n$ ($2 \le n \le 10^6$) — the length of the permutations.

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Output

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The only line should contain your answer modulo $10^9+7$.

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Note

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Consider the second example: these are the permutations of length $3$:

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  • $[1,2,3]$, $f(p)=1$.
  • $[1,3,2]$, $f(p)=1$.
  • $[2,1,3]$, $f(p)=2$.
  • $[2,3,1]$, $f(p)=2$.
  • $[3,1,2]$, $f(p)=2$.
  • $[3,2,1]$, $f(p)=2$.
翻译中…

The maximum value $f_{max}(3) = 2$, and there are $4$ permutations $p$ such that $f(p)=2$.

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样例

Input #1
2
Output #1
1
InputCopy OutputCopy
Input #2
3
Output #2
4
InputCopy OutputCopy
Input #3
6
Output #3
120
InputCopy OutputCopy
题目信息
题号
1174E
时间限制
2 s
内存限制
256 MB
标签
组合数学
动态规划
数学
数论

题面与样例版权归 Codeforces 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。