217. Contains Duplicate

Array Hash Table Sorting

Problem - 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

Explanation:

The element 1 occurs at the indices 0 and 3.

Example 2:

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

Output: false

Explanation:

All elements are distinct.

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

Solutions

Python3

class Solution:
    def containsDuplicate(self, nums: List[int]) -> bool:
        # count = Counter(nums)
        # return True if any(i > 1 for val, i in count.items()) else False
        nums_set = set(nums)

        if len(nums) == len(nums_set):
            return False
        return True

Submission Stats:

• Runtime: 3 ms (98.96%)
• Memory: 31.7 MB (29.39%)