Codeforces Round 648 (Div. 2)
C
Rotation Matching
Codeforces
1400
原题
← BD →
翻译中…

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 $b$.

翻译中…

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.

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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:

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  • $i = j$, that is, they are at the same index.
  • $a_i = b_j$
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His two disciples are allowed to perform the following operation any number of times:

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

翻译中…

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

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Input

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

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

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

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Output

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

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Note

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

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For the second case: The operation is not required. For all possible rotations of $a$ and $b$, the number of matching pairs won't exceed $1$.

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

翻译中…

样例

Input #1
5
1 2 3 4 5
2 3 4 5 1
Output #1
5
InputCopy OutputCopy
Input #2
5
5 4 3 2 1
1 2 3 4 5
Output #2
1
InputCopy OutputCopy
Input #3
4
1 3 2 4
4 2 3 1
Output #3
2
InputCopy OutputCopy
题目信息
题号
1365C
时间限制
1 s
内存限制
256 MB
标签
构造
数据结构
贪心
模拟

题面与样例版权归 Codeforces 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。