题库练习 Rotation Matching
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A13515 | Rotation Matching

时间限制1s
内存限制256MB
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题目描述

After the mysterious disappearance of Ashish, his two favourite disciples Ishika and Hriday, were each left with one half of a secret message. These messages can each be represented by a permutation of size $n$ . Let's call them $a$ and $b$ .

Note that a permutation of $n$ elements is a sequence of numbers $a_1, a_2, \ldots, a_n$ , in which every number from $1$ to $n$ appears exactly once.

The message can be decoded by an arrangement of sequence $a$ and $b$ , such that the number of matching pairs of elements between them is maximum. A pair of elements $a_i$ and $b_j$ is said to match if:

- $i = j$ , that is, they are at the same index.
- $a_i = b_j$

His two disciples are allowed to perform the following operation any number of times:

- choose a number $k$ and cyclically shift one of the permutations to the left or right $k$ times.

A single cyclic shift to the left on any permutation $c$ is an operation that sets $c_1:=c_2, c_2:=c_3, \ldots, c_n:=c_1$ simultaneously. Likewise, a single cyclic shift to the right on any permutation $c$ is an operation that sets $c_1:=c_n, c_2:=c_1, \ldots, c_n:=c_{n-1}$ simultaneously.

Help Ishika and Hriday find the maximum number of pairs of elements that match after performing the operation any (possibly zero) number of times.

输入格式

The first line of the input contains a single integer $n$ $(1 \le n \le 2 \cdot 10^5)$ — the size of the arrays.

The second line contains $n$ integers $a_1$ , $a_2$ , ..., $a_n$ $(1 \le a_i \le n)$ — the elements of the first permutation.

The third line contains $n$ integers $b_1$ , $b_2$ , ..., $b_n$ $(1 \le b_i \le n)$ — the elements of the second permutation.

输出格式

Print the maximum number of matching pairs of elements after performing the above operations some (possibly zero) times.

输入输出样例

输入 #1
5
1 2 3 4 5
2 3 4 5 1
输出 #1
5
输入 #2
5
5 4 3 2 1
1 2 3 4 5
输出 #2
1
输入 #3
4
1 3 2 4
4 2 3 1
输出 #3
2
C++ 编辑器
输入
输出