思考题 that is easier than #14

# Sort and Sort and Sort and Sort

You are given an integer array A of length N. And you are given Q queries. For each query, you are given Li and Ri.

You need to find out the sum of products of adjcent numbers in the sorted array A[Li,Ri]

# Example

A={1,2,3,4,5}

Q={[1,3],[2,4],[1,5]}

**Output**

8

18

40

**Explain**

# Constriants

Subtask 1(50%): The array is sorted

Subtask 2(50%): Nothing

N<=100000,Ai<=1e9

# Solution

See Ep.14