AtCoder Regular Contest 132
C
Almost Sorted
AtCoder
⌀ 1616
原题
← BD →
翻译中…

Problem Statement

翻译中…

Given is a sequence $a_1,\dots,a_n$ consisting of $1,\dots, n$ and $-1$, along with an integer $d$. How many sequences $p_1,\dots,p_n$ satisfy the conditions below? Print the count modulo $998244353$.

翻译中…
  • $p_1,\dots,p_n$ is a permutation of $1,\dots, n$.
  • For each $i=1,\dots,n$, $a_i=p_i$ if $a_i\neq -1$. (That is, $p_1,\dots,p_n$ can be obtained by replacing the $-1$s in $a_1,\dots,a_n$ in some way.)
  • For each $i=1,\dots,n$, $|p_i - i|\le d$.
翻译中…

Constraints

翻译中…
  • $1 \le d \le 5$
  • $d < n \le 500$
  • $1\le a_i \le n$ or $a_i=-1$.
  • $|a_i-i|\le d$ if $a_i\neq -1$.
  • $a_i\neq a_j$, if $i\neq j$ and $a_i, a_j \neq -1$.
  • All values in input are integers.
翻译中…

Input

翻译中…

Input is given from Standard Input in the following format:

翻译中…

n d
a_1 \dots a_n

翻译中…

Output

翻译中…

Print the number of sequences that satisfy the conditions, modulo $998244353$.

翻译中…

样例

Input #1
4 2
3 -1 1 -1
Output #1
2
The conditions are satisfied by $(3,2,1,4)$ and $(3,4,1,2)$.
Input #2
5 1
2 3 4 5 -1
Output #2
0
The only permutation of $1,2,3,4,5$ that can be obtained by replacing the $-1$ is $(2,3,4,5,1)$, whose fifth term violates the condition, so the answer is $0$.
Input #3
16 5
-1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1
Output #3
794673086
Print the count modulo $998244353$.
题目信息
题号
arc132_c
时间限制
2 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。