217. Contains Duplicate

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 <= 10^5
• -10^9 <= nums[i] <= 10^9

Approach

Solution

class Solution:
    def containsDuplicate(self, nums: List[int]) -> bool:
        return len(set(nums)) != len(nums)

Explanation