SOLVE
LATER
Given an array of size N, Velma give Scooby and Shaggy to compute the following sum on the array (0-indexed array).
,
where \(\lfloor.\rfloor\) is the floor operator.
Since it was taking too long for Scooby and Shaggy to compute the sum, they need your help.
Can you help them?
The first line of input will contain a single integer N, denoting the size of the array.
The second line will contain N integers arr_{0}, arr_{1}, arr_{2}, ..., arr_{n-1}.
Print a single integer, the answer to Velma's question.
Note: The answer will fit in signed 64-bit integer
The following triplets exists in the given array:
1 2 1
1 2 7
1 2 3
1 1 7
1 1 3
1 7 3
2 1 7
2 1 3
2 7 3
1 7 3
So, if we compute the required sum using these triplets, we get the sum to be equal to 6.