Solution: Maximum Difference Between Increasing Elements

Statement

Given an integer array nums, choose two indices i and j such that i < j and nums[i] < nums[j]. Define the value of this pair as nums[j] - nums[i].

Return the maximum value over all valid pairs. If no valid pair exists, return $-1$.

Note: A pair is valid only when the index order satisfies i < j.

Constraints: ...