시간 제한 | 메모리 제한 | 제출 | 정답 | 맞힌 사람 | 정답 비율 |
---|---|---|---|---|---|
2 초 | 512 MB | 19 | 12 | 10 | 58.824% |
Consider strings consisting of the brackets '(
' and ')
'.
The regular bracket sequences are the strings which can be obtained by the following rules:
(
$A$)
is a regular bracket sequence.You are given $N$ boxes numbered $1, 2, \ldots, N$, and also two integers, $M$ and $K$. Your task is to put exactly one regular bracket sequence in each of $N$ boxes such that the following conditions are met:
(
' brackets in all $N$ boxes is equal to $M$.Count the number of different ways to do that. Two distributions are considered different if there exists a number $i$ such that box $i$ contains different regular bracket sequences in those distributions.
Because the answer may be very large, print the answer modulo $998\,244\,353$.
The input contains one line with three integers $N$, $M$, and $K$ in it ($1 \le M, N \le 10^6$, $1 \le K \le M$).
Print the answer modulo $998\,244\,353$.
2 2 1
4
1 1 1
0
24 120 30
379268651
For the first example, the following distributions meet the conditions:
(())
, empty;()()
, empty;(())
;()()
.So, the answer is $4$.