[LeetCode (Easy)] 217. Contains Duplicate - Arrays and Hashmaps

217. Contains Duplicate

Easy

---

Given an integer array nums, return true if any value appears at least twice in the array, and return false if every element is distinct.

 

Example 1:

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

Example 2:

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

Example 3:

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

 

Constraints:

• 1 <= nums.length <= 105
• -109 <= nums[i] <= 109

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