[NeetCode 150] Duplicate Integer

Duplicate Integer

Given an integer array nums, return true if any value appears more than once in the array, otherwise return false.

Example 1:

Input: nums = [1, 2, 3, 3]

Output: true

Example 2:

Input: nums = [1, 2, 3, 4]

Output: false

Solution

To find duplications, hash algorithm is easy to think of using a hash algorithm. In python, a set structure can be easily applied.

Code

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