P24713 [AtCoder] Alone
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题目描述

Problem Statement

You are given an integer sequence $A = (A_1, A_2, \ldots, A_N)$.
Find the number of pairs of integers (L, R) that satisfy the following conditions:

  • $1 \leq L \leq R \leq N$
  • There is a number that appears exactly once among $A_L, A_{L + 1}, \ldots, A_R.$ More precisely, there is an integer x such that exactly one integer i satisfies A_i = x and $L \leq i \leq R$.

Input

The input is given from Standard Input in the following format:
N
$A_1 A_2 \ldots A_N$

Output

Print the answer.

Constraints

  • $2 \leq N \leq 2 \times 10^5$
  • $1 \leq A_i \leq N$
  • All input values are integers.

Sample Input 1

5
2 2 1 2 1

Sample Output 1

12

12 pairs of integers satisfy the conditions: (L, R) = (1, 1), (1, 3), (1, 4), (2, 2), (2, 3), (2, 4), (3, 3), (3, 4), (3, 5), (4, 4), (4, 5), (5, 5).

Sample Input 2

4
4 4 4 4

Sample Output 2

4

Sample Input 3

10
1 2 1 4 3 3 3 2 2 4

Sample Output 3

47

输入格式

见题面 Input 部分

输出格式

见题面 Output 部分

样例输入
5 2 2 1 2 1
样例输出
12