BinarySearch 0273 A Number and Its Triple

Problem statement

https://binarysearch.com/problems/A-Number-and-Its-Triple/

Solution

Just use counter, be careful with x = 0 case.

Complexity

It is O(n) for time and space.

Code

class Solution:
    def solve(self, nums):
        cnt = Counter(nums)
        for x in nums:
            if (x != 0 and 3*x in cnt) or (x == 0 and cnt[x] >= 2): return True
        return False