Codeforces Round 902 (Div. 1, based on COMPFEST 15 - Final Round)
B
Effects of Anti Pimples
Codeforces
1500
原题
← AC →
翻译中…

Chaneka has an array $[a_1,a_2,\ldots,a_n]$. Initially, all elements are white. Chaneka will choose one or more different indices and colour the elements at those chosen indices black. Then, she will choose all white elements whose indices are multiples of the index of at least one black element and colour those elements green. After that, her score is the maximum value of $a_i$ out of all black and green elements.

翻译中…

There are $2^n-1$ ways for Chaneka to choose the black indices. Find the sum of scores for all possible ways Chaneka can choose the black indices. Since the answer can be very big, print the answer modulo $998\,244\,353$.

翻译中…

Input

翻译中…

The first line contains a single integer $n$ ($1 \leq n \leq 10^5$) — the size of array $a$.

翻译中…

The second line contains $n$ integers $a_1,a_2,a_3,\ldots,a_n$ ($0\leq a_i\leq10^5$).

翻译中…

Output

翻译中…

An integer representing the sum of scores for all possible ways Chaneka can choose the black indices, modulo $998\,244\,353$.

翻译中…

Note

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In the first example, below are the $15$ possible ways to choose the black indices:

翻译中…
  • Index $1$ is black. Indices $2$, $3$, and $4$ are green. Maximum value among them is $19$.
  • Index $2$ is black. Index $4$ is green. Maximum value among them is $14$.
  • Index $3$ is black. Maximum value among them is $19$.
  • Index $4$ is black. Maximum value among them is $9$.
  • Indices $1$ and $2$ are black. Indices $3$ and $4$ are green. Maximum value among them is $19$.
  • Indices $1$ and $3$ are black. Indices $2$ and $4$ are green. Maximum value among them is $19$.
  • Indices $1$ and $4$ are black. Indices $2$ and $3$ are green. Maximum value among them is $19$.
  • Indices $2$ and $3$ are black. Index $4$ is green. Maximum value among them is $19$.
  • Indices $2$ and $4$ are black. Maximum value among them is $14$.
  • Indices $3$ and $4$ are black. Maximum value among them is $19$.
  • Indices $1$, $2$, and $3$ are black. Index $4$ is green. Maximum value among them is $19$.
  • Indices $1$, $2$, and $4$ are black. Index $3$ is green. Maximum value among them is $19$.
  • Indices $1$, $3$, and $4$ are black. Index $2$ is green. Maximum value among them is $19$.
  • Indices $2$, $3$, and $4$ are black. Maximum value among them is $19$.
  • Indices $1$, $2$, $3$, and $4$ are black. Maximum value among them is $19$.
翻译中…

The total sum is $19+14+19+9+19+19+19+19+14+19+19+19+19+19+19 = 265$.

翻译中…

样例

Input #1
4
19 14 19 9
Output #1
265
InputCopy OutputCopy
Input #2
1
0
Output #2
0
InputCopy OutputCopy
Input #3
15
90000 9000 99000 900 90900 9900 99900 90 90090 9090 99090 990 90990 9990 99990
Output #3
266012571
InputCopy OutputCopy
题目信息
题号
1876B
时间限制
2 s
内存限制
256 MB
标签
组合数学
数论
排序

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。