Contains Duplicate

217. Contains Duplicate

Difficulty: Easy

Related Topics: Array, Hash Table, Sorting

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

Code:

class Solution:
    def containsDuplicate(self, nums: List[int]) -> bool:
        numset=set(nums)
        if len(nums) == len(numset):
            return False
        else:
            return True

Feedbacks:

I first converted a list to set, because set doesn’t have duplicates. Then, I compared the length of set and list, so if there’s no difference between two, it means there are no duplicates in list so return False, and vice versa.