CF1365C.Rotation Matching

普及/提高-

通过率:0%

AC君温馨提醒

该题目为【codeforces】题库的题目,您提交的代码将被提交至codeforces进行远程评测,并由ACGO抓取测评结果后进行展示。由于远程测评的测评机由其他平台提供,我们无法保证该服务的稳定性,若提交后无反应,请等待一段时间后再进行重试。

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 nn . Let's call them aa and bb .

Note that a permutation of nn elements is a sequence of numbers a1,a2,,ana_1, a_2, \ldots, a_n , in which every number from 11 to nn appears exactly once.

The message can be decoded by an arrangement of sequence aa and bb , such that the number of matching pairs of elements between them is maximum. A pair of elements aia_i and bjb_j is said to match if:

  • i=ji = j , that is, they are at the same index.
  • ai=bja_i = b_j

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

  • choose a number kk and cyclically shift one of the permutations to the left or right kk times.

A single cyclic shift to the left on any permutation cc is an operation that sets c1:=c2,c2:=c3,,cn:=c1c_1:=c_2, c_2:=c_3, \ldots, c_n:=c_1 simultaneously. Likewise, a single cyclic shift to the right on any permutation cc is an operation that sets c1:=cn,c2:=c1,,cn:=cn1c_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 nn (1n2105)(1 \le n \le 2 \cdot 10^5) — the size of the arrays.

The second line contains nn integers a1a_1 , a2a_2 , ..., ana_n (1ain)(1 \le a_i \le n) — the elements of the first permutation.

The third line contains nn integers b1b_1 , b2b_2 , ..., bnb_n (1bin)(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

说明/提示

For the first case: bb can be shifted to the right by k=1k = 1 . The resulting permutations will be {1,2,3,4,5}\{1, 2, 3, 4, 5\} and {1,2,3,4,5}\{1, 2, 3, 4, 5\} .

For the second case: The operation is not required. For all possible rotations of aa and bb , the number of matching pairs won't exceed 11 .

For the third case: bb can be shifted to the left by k=1k = 1 . The resulting permutations will be {1,3,2,4}\{1, 3, 2, 4\} and {2,3,1,4}\{2, 3, 1, 4\} . Positions 22 and 44 have matching pairs of elements. For all possible rotations of aa and bb , the number of matching pairs won't exceed 22 .

首页