Get Mean Rank Count

Problem Overview

• Given rank, a permutation of 1..n, compute for each x in 1..n how many contiguous subarrays have mean rank exactly x.
• Input: rank[1..n], 1 ≤ n ≤ 10^3, all distinct; Output: int[n] where the i-th entry is the count for mean i.
• Context: Groups represent students with consecutive roll numbers in an Amazon Academy scholarship test.
• Source: Asked in Amazon interviews; this is a coding interview problem and a common interview question.