A9997. Superior Periodic Subarrays
编程题
普及/提高-
知识点
题目描述
You are given an infinite periodic array $a_{0},a_{1},...,a_{n-1},...$ with the period of length $n$ . Formally, . A periodic subarray $(l,s)$ ( $0<=l<n$ , $1<=s<n$ ) of array $a$ is an infinite periodic array with a period of length $s$ that is a subsegment of array $a$ , starting with position $l$ .
A periodic subarray $(l,s)$ is superior, if when attaching it to the array $a$ , starting from index $l$ , any element of the subarray is larger than or equal to the corresponding element of array $a$ . An example of attaching is given on the figure (top — infinite array $a$ , bottom — its periodic subarray $(l,s)$ ):
Find the number of distinct pairs $(l,s)$ , corresponding to the superior periodic arrays.
A periodic subarray $(l,s)$ is superior, if when attaching it to the array $a$ , starting from index $l$ , any element of the subarray is larger than or equal to the corresponding element of array $a$ . An example of attaching is given on the figure (top — infinite array $a$ , bottom — its periodic subarray $(l,s)$ ):
Find the number of distinct pairs $(l,s)$ , corresponding to the superior periodic arrays.
输入格式
The first line contains number $n$ ( $1<=n<=2·10^{5}$ ). The second line contains $n$ numbers $a_{0},a_{1},...,a_{n-1}$ ( $1<=a_{i}<=10^{6}$ ), separated by a space.
输出格式
Print a single integer — the sought number of pairs.
输入输出样例
输入 #1
4 7 1 2 3
输出 #1
2
输入 #2
2 2 1
输出 #2
1
输入 #3
3 1 1 1
输出 #3
6
说明/提示
In the first sample the superior subarrays are (0, 1) and (3, 2).
Subarray (0, 1) is superior, as $a_{0}>=a_{0},a_{0}>=a_{1},a_{0}>=a_{2},a_{0}>=a_{3},a_{0}>=a_{0},...$
Subarray (3, 2) is superior $a_{3}>=a_{3},a_{0}>=a_{0},a_{3}>=a_{1},a_{0}>=a_{2},a_{3}>=a_{3},...$
In the third sample any pair of $(l,s)$ corresponds to a superior subarray as all the elements of an array are distinct.
Subarray (0, 1) is superior, as $a_{0}>=a_{0},a_{0}>=a_{1},a_{0}>=a_{2},a_{0}>=a_{3},a_{0}>=a_{0},...$
Subarray (3, 2) is superior $a_{3}>=a_{3},a_{0}>=a_{0},a_{3}>=a_{1},a_{0}>=a_{2},a_{3}>=a_{3},...$
In the third sample any pair of $(l,s)$ corresponds to a superior subarray as all the elements of an array are distinct.