Find Maximum Greatness

Problem Overview

• Task: Rearrange an array to maximize greatness, the number of indices i where rearranged[i] > arr[i].
• Input/Output: Given int array arr, return the maximum greatness as an integer; constraints: 1 ≤ n ≤ 1e5, 1 ≤ arr[i] ≤ 1e9.
• Context: Models outperforming an original ordering; relevant to ranking, matching, or allocation scenarios.
• Source: From Twilio interviews; a coding interview problem frequently used as an interview question.