C++ basics

solution.cpp

class Solution {
  vector<int> a;
public:
  Solution(vector<int> nums) : a(nums) {}

  /** Resets the array to its original configuration and return it. */
  vector<int> reset() { return a; }

  /** Returns a random shuffling of the array. */
  vector<int> shuffle() {
    auto r = a;
    for (size_t i = 1; i < r.size(); i++)
      swap(r[rand()%(i+1)], r[i]);
    return r;
  }
};

vector<int> input;   
Solution a(input);   
vector<int> v1 = a.reset();  
vector<int> v2 = a.shuffle();