Given an array of integers arr, return true if the number of occurrences of each value in the array is unique, or false otherwise.
In other words, no two different values in the array should appear the same number of times.
1 <= arr.length <= 1000-1000 <= arr[i] <= 1000arr = [1,2,2,1,1,3]truearr = [1,2]falsearr = [-3,0,1,-3,1,1,1,-3,10,0]true