217. Contains Duplicate
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.
links to related : 219 Contains Duplicate II
public class Solution {
public boolean containsDuplicate(int[] nums) {
Set<Integer> set = new HashSet<>();
for(int val : nums){
if(set.contains(val)) return true;
set.add(val);
}
return false;
}
}