Problem 2: Contains Duplicate (easy)

Problem Statement

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, 4]
Output: false  
Explanation: There are no duplicates in the given array.

Example 2:

Input: nums= [1, 2, 3, 1]
Output: true  
Explanation: '1' is repeating.

Constraints:

• 1 <= nums.length <= 10^5
•  -10^9 <= nums[i] <= 10^9

Try it yourself