bubble sort - array

#include <iostream>
#include <array>
#define N 10

using namespace std;

void swap (int& a, int& b)
{
    int aux = a;
    a = b;
    b = aux;
}

void bubble_sort2 (array<int,N>& a) // recomendado
{
    bool swapped;
    for (int i = 0; i < N-1; i++)
    {
        swapped = false;
        for (int j=N-1; j > i; j--)
            if (a.at(j) < a.at(j-1))
            {
                swap (a.at(j),a.at(j-1));
                swapped = true;
            }
        if (not swapped)
            break;
    }
}

void bubble_sort (array<int,N>& a) // y el ganador es este
{
    int c = 0;
    for (int i = N-1; i > 0; i--)
        for (int j=0; j < i; j++)
        {
            if (a.at(j) > a.at(j+1))
                swap (a.at(j),a.at(j+1));
            c++;
        }
    cout << c << endl;
}

void printarray (array<int,N>& a)
{
    for (int i=0; i<N; i++)
        cout << a.at(i) << " ";
    cout << "\n";
}

int main()
{
    array<int,N> arr = {6,7,8,9,10,5,4,3,2,1};
    bubble_sort(arr);
    printarray(arr);

    return 0;
}