Leetcode Shuffle

#include <iostream>
#include <vector>

using namespace std;

vector < int >
shuffle (vector < int >&nums, int n)
{
    for (int i = n; i < nums.size (); i++)
    {
        nums[i] = (nums[i] << 16) | nums[i - n];
    }
    for (int i = n, id = 0; i < nums.size (); i++, id += 2)
    {
        nums[id] = nums[i] & 0xffff;
        nums[id + 1] = nums[i] >> 16;
    }

    return nums;
}

int
main ()
{
    vector < int >nums = { 2, 5, 1, 3, 4, 7 };
    int n = 3;
    vector < int >ans = shuffle (nums, n);
    for (auto x:ans)
    {
        cout << x << " ";
    }
}