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.

Example 1:

Input: nums = [1,2,3,3]
Output: 3

Example 2:

Input: nums = [2,1,2,5,3,2]
Output: 2

Example 3:

Input: nums = [5,1,5,2,5,3,5,4]
Output: 5

Constraints:

• 2 <= n <= 5000


• nums.length == 2 * n


• 0 <= nums[i] <= 104


• nums contains n + 1 unique elements and one of them is repeated exactly n times.