Maximum Sum Triplet

Given an array A containing N integers.

You need to find the maximum sum of triplet ( A_i + A_j + A_k ) such that 0 <= i < j < k < N and A_i < A_j < A_k.

If no such triplet exist return 0.

3 <= N <= 10⁵.

1 <= A[i] <= 10⁸.

First argument is an integer array A.

Return a single integer denoting the maximum sum of triplet as described in the question.

Input 1:

 A = [2, 5, 3, 1, 4, 9]

Input 2:

 A = [1, 2, 3]

Output 1:

 16

Output 2:

 6

Explanation 1:

 All possible triplets are:-
    2 3 4 => sum = 9
    2 5 9 => sum = 16
    2 3 9 => sum = 14
    3 4 9 => sum = 16
    1 4 9 => sum = 14
  Maximum sum = 16

Explanation 2:

 All possible triplets are:-
    1 2 3 => sum = 6
 Maximum sum = 6