Blind 75: contains Duplicate
https://leetcode.com/problems/contains-duplicate/description/
class Solution:
def containsDuplicate(self, nums: List[int]) -> bool:
hashset = set()
for num in nums:
if num in hashset:
return True
hashset.add(num)
return False
Explanation
To check if there is a duplicate, check if we have already seen the current element by checking a hashset of previously seen elements.
Time Complexity = O(N) because we only need to iterate through nums once.
Space Complexity = O(N) because we only need to store ~N elements in the hashset.