USE C++

2 FILES: ONE header file (h) and one cpp File

7. Given an array of integers, 1 s alil s n (n size of array), some elements appear twice and others appear once. Find all the elements that appear twice in this array. (10) nput [4,3,2,7,8,2,3,1] Output: 12,3] Please implement your solution with given class: class Solution ( public: vector findDuplicates(vector& nums) // your method here