数组振幅通过php函数。

I have this question, which I need to solve, help needed please. A non-empty zero-indexed array A consisting of N integers is given. The amplitude of this array is defined as the largest possible difference between two of its elements, i.e.: amplitude(A) = max{ A[P] − A[Q] : 0 ≤ P, Q < N }I have this question, which I need to solve, he