Description
Given an array of integers arr, return true if the number of occurrences of each value in the array is unique, or false otherwise.
Examples
Input:
arr = [1,2,2,1,1,3]Output:
trueExplanation:
1→3, 2→2, 3→1, all unique.
Input:
arr = [1,2]Output:
falseExplanation:
Each value appears once, so occurrence counts are [1, 1]. The counts are not unique.
Input:
arr = [5,5,5,7,7,8]Output:
trueExplanation:
Number 5 appears 3 times, number 7 appears 2 times, and number 8 appears 1 time. The occurrence counts are [3,2,1] which are all unique, so return true.
Constraints
- •
1 ≤ arr.length ≤ 1000