Given an array A of N integers. Your task is to write a program to find the maximum value of ∑arr[i]*i, where i = 0, 1, 2,…., n – 1.
You are allowed to rearrange the elements of the array. Note: Since output could be large, hence module 109+7 and then print answer.
First line of the input contains an integer T, denoting the number of test cases. Then T test case follows. Each testcase contains two lines of input. First line contains an integer N, denoting the size of the array. Next line contains N space separated integers denoting the elements of the array.
For each test case, print the required answer on a new line.
1 <= T <= 103
1 <= N <= 107
1 <= Ai <= N
Explanation: Testcase1: If we arrange the array as 1 2 3 4 5 then we can see that the minimum index will multiply with minimum number and maximum index will multiply with maximum number. So 1*0+2*1+3*2+4*3+5*4=0+2+6+12+20 =40 mod(109+7) = 40