[Leet Code] Unique Number of Occurrences
Jan 2, 2021
Leetcode: https://leetcode.com/problems/unique-number-of-occurrences/
Problem:
Given an array of integers arr
, write a function that returns true
if and only if the number of occurrences of each value in the array is unique.
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
Solution:
class Solution(object):
def uniqueOccurrences(self, arr):
"""
:type arr: List[int]
:rtype: bool
"""
answers = []
for i in set(arr):
answers.append(arr.count(i))
return len(answers) == len(set(answers))