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]
Subtask 1(50%): The array is sorted
Subtask 2(50%): Nothing