题库练习 Divisor Set
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A12979 | Divisor Set

时间限制1s
内存限制256MB
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题目描述

You are given an integer $x$ represented as a product of $n$ its prime divisors $p_1 \cdot p_2, \cdot \ldots \cdot p_n$ . Let $S$ be the set of all positive integer divisors of $x$ (including $1$ and $x$ itself).

We call a set of integers $D$ good if (and only if) there is no pair $a \in D$ , $b \in D$ such that $a \ne b$ and $a$ divides $b$ .

Find a good subset of $S$ with maximum possible size. Since the answer can be large, print the size of the subset modulo $998244353$ .

输入格式

The first line contains the single integer $n$ ( $1 \le n \le 2 \cdot 10^5$ ) — the number of prime divisors in representation of $x$ .

The second line contains $n$ integers $p_1, p_2, \dots, p_n$ ( $2 \le p_i \le 3 \cdot 10^6$ ) — the prime factorization of $x$ .

输出格式

Print the maximum possible size of a good subset modulo $998244353$ .

输入输出样例

输入 #1
3
2999999 43 2999957
输出 #1
3
输入 #2
6
2 3 2 3 2 2
输出 #2
3
C++ 编辑器
输入
输出