N-Repeated Element in Size 2N Array

You are given an integer array nums with the following properties:

• nums.length == 2 * n.

• nums contains n + 1 unique elements.

• Exactly one element of nums is repeated n times.

Return the element that is repeated n times.

LeetCode Problem - 961

class Solution {
    public int repeatedNTimes(int[] nums) {
        // Create a HashSet to keep track of seen elements
        Set<Integer> set = new HashSet<>();

        // Iterate through each element in the nums array
        for (int ele : nums) {
            // Check if the current element is already in the set
            if (set.contains(ele)) {
                // If it is, this is the repeated element, return it
                return ele;
            }
            // Otherwise, add the current element to the set
            set.add(ele);
        } 

        // Return -1 if no repeated element is found (shouldn't happen per problem statement)
        return -1;
    }
}