Hello!

Today I have a problem. After a while, the problem turned into finding 3 elements with indice $$$i, j, k$$$ in an array $$$A$$$ of size $$$n$$$ that:

• $$$1 ≤ i < j < k ≤ n$$$
• $$$2 * j = i + k$$$
• $$$n ≤ 2*10^5$$$
• $$$A_i ≤ 10^9$$$

and $$$A_i + A_j + A_k$$$ is maximum possible!

I wonder if the problem can be solved in a way better than the naive $$$O(n ^ 2)$$$ solution. Thank guys!