1207. Unique Number of Occurrences

Given an array of integers arr, return true if the number of occurrences of each value in the array is unique or false otherwise.

Example 1:

Input: arr = [1,2,2,1,1,3]
Output: true
Explanation: The value 1 has 3 occurrences, 2 has 2 and 3 has 1. No two values have the same number of occurrences.

Example 2:

Input: arr = [1,2]
Output: false

Example 3:

Input: arr = [-3,0,1,-3,1,1,1,-3,10,0]
Output: true

def uniqueOccurrences(self, arr: List[int]) -> bool:
        dic = {}
        for i in arr:
            if i in dic:
                dic[i]+=1
            else:
                dic[i]=1

        li=list(dic.values())
        li.sort()

        for j in range(len(li)-1):
            if li[j]==li[j+1]:
                return False
        return True