Sorting bubble

#include <iostream>
#include <ctime>

using std::cout;
using std::cin;
using std::endl;

int exchange(int &a, int &b);

void main()
{
    srand(time(NULL));
    const int size = 10;
    int arr[size];

    for (int i = 0; i < size; i++)
    {
        arr[i] = rand() % 10;
        cout << arr[i] << "\t";
    }


    for (int i = 0; i < size; i++)
    {
        for (int j = 0; j < size; j++)
        {
            if (arr[j] < arr[j + 1])
            {
                /*arr[j] = arr[j] + arr[j + 1];
                arr[j + 1] = arr[j] - arr[j + 1];
                arr[j] = arr[j] - arr[j + 1];*/
                exchange(arr[j], arr[j + 1]);   //int a = arr[j], int b = arr[j+1]
            }
        }
    }

    cout << endl << endl;

    for (int i = 0; i < size; i++)
    {
        cout << arr[i] << "\t";
    }

    cout << endl << endl;
}

int exchange(int &a, int &b)
{
    int c = a;
    a = b;
    b = c;

    return 0;
}