Contains Duplicate

Given int array, return true if any value appears more than once in array, otherwise return false

Hash set

def hasDuplicate(nums: List[int]) -> bool:
	seen = set()
	for num in nums:
		if num in seen:
			return True
		seen.add(num)
	return False

Hash set length

def hasDuplicate(nums: List[int]) -> bool:
	return len(set(nums)) < len(nums)