Contains Duplicate
Given an array of integers nums, return true if any value appears more than once in the array, otherwise return false.
Example 1:
Input: nums = [1, 2, 3, 3] Output: true
Example 2:
Input: nums = [1, 2, 3, 4] Output: false
Recommended time and space complexity
You should aim for a solution with O(n) time complexity and O(n) space complexity, where n is the size of the input array.
Hint 1
A brute force solution would be to check every element against every other element in the array. This would be an O(n^2) time complexity solution. Can you think of a more efficient way?
Hint 2
Is it possible to check if an element is a duplicate without comparing it to every other element? Perhaps some data structure would be useful here.
Hint 3
We can use a hash data structure, such as a hash table or hash map, to store elements we've already seen. This will allow us to check if an element is a duplicate in constant time.