For this one, we’re returning a boolean if the frequency of each integer within the input array is unique.
The solution is as follows:
from collections import Counter
class Solution:
def uniqueOccurrences(self, arr: List[int]) -> bool:
counts = Counter(arr).values()
return len(counts) == len(set(counts))_ Time Complexity:
O(n) - We have to iterate through the entire input array to count frequencies.
_ Space Complexity:
O(n) - We store the frequency of each number in the input array.