Из массивов А (20) и С (20) образовать новый массив Х={a1,c1,a2,c2,…,a20,c20}

#include <iostream>
#include <cstdlib>
#include <ctime>
const int n = 20;
using namespace std;
int main() {
    srand(time(NULL));
    int A[n],C[n],X[2*n];
    int i,j;
    for (i=0; i<n; i++) {
        A[i] = rand()%20;
        C[i] = rand()%30;
    }
    for (i=0; i<n; i++) cout << A[i] << " ";
    cout << endl;
    for (i=0; i<n; i++) cout << C[i] << " ";
    cout << endl;
    cout << endl;
    for (i=0,j=0; i<n; i++,j=j+2) X[j] = A[i];
    for (i=0,j=1; i<n; i++,j=j+2) X[j] = C[i];
    for (i=0; i<2*n; i++)   cout << X[i] << " ";
    
    return 0;
}

#include <algorithm>
#include <iostream>
#include <iterator>
#include <vector>
 
template < typename RAIterator, typename output_iterator >
void my_merge(RAIterator first, RAIterator last, RAIterator second, output_iterator output)
{
    while (first != last)
    {
        *output++ = *first++;
        *output++ = *second++;
    }
}
 
int main()
{
    const std::size_t size = 20;
    int a[size] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
        11, 12, 13, 14, 15, 16, 17, 18, 19, 20 };
    int b[size] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
        11, 12, 13, 14, 15, 16, 17, 18, 19, 20 };
    std::vector<int> result;
    my_merge(std::begin(a), std::end(a), std::begin(b), std::back_inserter(result));
    std::copy(result.begin(), result.end(), std::ostream_iterator<int>(std::cout, " "));
    std::cout << std::endl;
    return 0;
}