Subarrays

1

1 votes
Easy
Problem

You are given an array of size n. Find out how many subarrays exist, such that the first and last element of the subarray is the same, with at least 2 elements in each subarray.

A subarray is a order-wise continuous subset of an array. For the array [1,2,3,4,5], valid subarrays include [1,2,3], [2,3,4,5], [1,2], [4,5] whereas [1,3,5] , [2,1] etc. are not subarrays.

Repeating elements in a subarray are considering distinct at distinct positions. That is, if the subarray [1,2,1] comes twice in an array, it is to be counted distinctly.

Input

  • First line will contain n, the size of the array.
  • The next line will contain n space separated integers  ai, denoting each element in the array.

Constraints

  • 1n106
  • 1ai109

Output

Single line containing the number of possible subarrays.

Time Limit: 2
Memory Limit: 256
Source Limit:
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