217. Contain Duplicates

🟩 Easy

Question

Given an array of integers, find if the array contains any duplicates.

Your function should return true if any value appears at least twice in the array, and it should return false if every element is distinct.

Example 1:

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

Example 2:

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

Example 3:

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

Complexity

• Time complexity: O(n)

• Space complexity: O(n)

Code

def containsDuplicate(self, nums: List[int]) -> bool:
    map = {} 
    for num in nums: 
        if map.get(num):
            return True
        map[num] = 1
    return False

def containsDuplicate(self, nums: List[int]) -> bool:
    return len(set(nums)) < len(nums)