Maximize Diversity of an Array

You are given an array $A$. The diversity of the array $A$ is defined as number of pairs $i, j, i < j $ such that $A_i \neq A_j$. You want to maximize the diversity of the array. For that, you are allowed to make at most $K$ operations on it, in any of which, you can select a particular element and change its value to any integer in the range 1 to $10^9$, both inclusive. Find out the maximum di