第四回日本最強プログラマー学生選手権-予選-(AtCoder Beginner Contest 313)
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Problem Statement

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$(2N+1)$ people are forming two rows to take a group photograph. There are $N$ people in the front row; the $i$-th of them has a height of $A_i$. There are $(N+1)$ people in the back row; the $i$-th of them has a height of $B_i$. It is guaranteed that the heights of the $(2N+1)$ people are distinct. Within each row, we can freely rearrange the people.

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Suppose that the heights of the people in the front row are $a_1,a_2,\dots,a_N$ from the left, and those in the back row are $b_1,b_2,\dots,b_{N+1}$ from the left. This arrangement is said to be good if all of the following conditions are satisfied:

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  • $a_i < b_i$ or $a_{i-1} < b_i$ for all $i\ (2 \leq i \leq N)$.
  • $a_1 < b_1$.
  • $a_N < b_{N+1}$.
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Among the $N!$ ways to rearrange the front row, how many of them, modulo $998244353$, are such ways that we can rearrange the back row to make the arrangement good?

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Constraints

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  • $1\leq N \leq 5000$
  • $1 \leq A_i,B_i \leq 10^9$
  • $A_i \neq A_j\ (1 \leq i < j \leq N)$
  • $B_i \neq B_j\ (1 \leq i < j \leq N+1)$
  • $A_i \neq B_j\ (1 \leq i \leq N, 1 \leq j \leq N+1)$
  • All input values are integers.
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Input

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The input is given from Standard Input in the following format:

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N
A_1 A_2 \dots A_N
B_1 B_2 \dots B_{N+1}

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Output

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Print the answer as an integer.

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样例

Input #1
3
1 12 6
4 3 10 9
Output #1
2
- When $a = (1,12,6)$, we can let, for example, $b = (4,3,10,9)$ to make the arrangement good. - When $a = (6,12,1)$, we can let, for example, $b = (10,9,4,3)$ to make the arrangement good. - When $a$ is one of the other four ways, no rearrangement of the back row (that is, none of the possible $24$ candidates of $b$) makes the arrangement good. Thus, the answer is $2$.
Input #2
1
5
1 10
Output #2
0
Input #3
10
189330739 910286918 802329211 923078537 492686568 404539679 822804784 303238506 650287940 1
125660016 430302156 982631932 773361868 161735902 731963982 317063340 880895728 1000000000 707723857 450968417
Output #3
3542400
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。