calculateMaxMinusMinOfAllSubsequence2

Given an array a with n elements.
A subsequence [l,r] (1 ≤ l ≤ r ≤ n) of  a is a sequence whose elements are al, al+1, … , ar.
u is the largest total element of the subsequece.
v is the smallest total number of subsequece.
Calculate u-v.

Example:

• For a={2, 1, 4}, the output should be calculateMaxMinusMinOfAllSubsequence2(a)=7. Explain:
  u=max[1,1]+max[1,2]+max[1,3]+max[2,2]+max[2,3]+max[3,3]
=2+2+4+1+4+4
=17
v=min[1,1]+min[1,2]+min[1,3]+min[2,2]+min[2,3]+min[3,3]
=2+1+1+1+1+4
=10
u-v=17-10=7

Input/Output:

• [Execution time limit] 0.5s in C++, 3s in Java and C#, 4s in Python, GO and Js

• [Input] integer.arrays a
  1 <= a.size() <= 105
-103 <= a[i] <= 103

• [Output] long
  Calculate u-v.