ALGO ARTIS プログラミングコンテスト2023 秋 (AtCoder Regular Contest 168)
翻译中…
Problem Statement
翻译中…
You are given a string $S$ of length $N$ consisting of the characters A, B, and C.
翻译中…
Consider performing the following operation between $0$ and $K$ times, inclusive:
翻译中…
- Freely choose two characters in
$S$and swap them.
翻译中…
Find the number of strings that $S$ can be after the operations, modulo $998244353$.
翻译中…
Constraints
翻译中…
$1 \leq N \leq 250000$$1 \leq K \leq 100$$S$is a string of length$N$consisting of the charactersA,B, andC.- All input values are integers.
翻译中…
Input
翻译中…
The input is given from Standard Input in the following format:
翻译中…
N K
S
翻译中…
Output
翻译中…
Print the answer.
翻译中…
样例
Input #1
3 1
ABC
Output #1
4
The following four strings can be obtained:
- $S=$`ABC`: No operation is needed.
- $S=$`BAC`: Swap the $1$-st and $2$-nd characters.
- $S=$`CBA`: Swap the $1$-st and $3$-rd characters.
- $S=$`ACB`: Swap the $2$-nd and $3$-rd characters.
Input #2
3 2
ABC
Output #2
6
Input #3
4 5
AAAA
Output #3
1
Input #4
30 10
CACCABAABBABABBCBBCAAACAAACCCA
Output #4
42981885
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。