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

Question

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

Constraints:

  • 1 <= arr.length <= 1000
  • -1000 <= arr[i] <= 1000

Python Solution

class Solution:
    def uniqueOccurrences(self, arr: List[int]) -> bool:
        d={}
        for i in arr:
            if i not in d:
                d[i]=1
            else:
                d[i]+=1
        s=set()
        for k,v in d.items():
            s.add(v)

        return (len(s)==len(d))
Abhishek Sharma
Abhishek Sharma

Started my Data Science journey in my 2nd year of college and since then continuously into it because of the magical powers of ML and continuously doing projects in almost every domain of AI like ML, DL, CV, NLP.

Articles: 520

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