Problem Description
You are given an array of size N.
Let us define the value of subsequence as the product of its elements.
Find the sum of values of all distinct subsequences. since the answer can be large return it modulo 10^9+7.
Constraints:
- 1 <= N <= 10^5
- 1 <= A[i] <= 10^6
Sample input:
N = 3, A = [1,2,3] Ans = 23 There are 7 distinct subsequences 3, 2, 1, 3*2 = 6, 3*1 = 3, 2*1 = 2, 3*2*1 = 6 then 3+2+1+6+3+2+6 = 23.
N = 3, A = [3, 2, 2] Ans = 27 There are 5 distinct subsequences
