selection sort algorithm with brute force method and recursive algorithm

The results:

The array a:
  0
  1
  2
  3
  4
  5

The codes:

//selection sort
#include<iostream>
#include<iomanip>
using namespace std;
void selection_sort(int a[], int n);
void display_selection(int a[], int n);
void swap_selection(int &n1, int &n2); //Remember that n1 and n2 are the arguments that cannot be transferred 
int main()
{
    int a[] = {2,3,4,5,0,1};
    int n = 6;
    selection_sort(a,n);
    display_selection(a,n);
    return 0;
}
void selection_sort(int a[], int n)
{
    int k;
    for(int i=0; i<n; i++){
        k = i;
        for(int j=i+1; j<n; j++){
            if(a[j]<a[k]){
                k = j;
            }
        }
        swap_selection(a[i], a[k]);
    }
}
void display_selection(int a[], int n)
{
    cout << "The array a:"<<endl;
    for(int i=0; i<n; i++){
        cout <<setw(3) <<a[i] <<endl;
    }
}
void swap_selection(int &n1, int &n2)
{
    int temp = n1;
    n1 = n2;
    n2 = temp;
}

The outputs:

The original array is:
The array a : 
   4   6   2   6  53   2   6  12
The array after the selection is:
The array a : 
   2   2   4   6   6   6  12  53

The codes:

// obtain the results from  the selection sort function by recrusive methods
#include<iostream>
#include<iomanip>
void swap(int &i, int &j);
void selectionSort(int a[], int n);
void displaySelection(int a[], int n);
using namespace std;
int main()
{
    int a[] = {4,6,2,6,53,2,6,12};
    int n = sizeof(a) / sizeof(a[0]);
    cout << "The original array is:" <<endl;
    displaySelection(a, n);
    selectionSort(a, n);
    cout << "\nThe array after the selection is:" <<endl;
    displaySelection(a, n);
    return 0;
}
void selectionSort(int a[], int n)
{
    if(n ==1){
        return ;
    }
    selectionSort(a,n-1);
    if(a[n-1] < a[n-2]){
        swap(a[n-1],a[n-2]);
    }
    selectionSort(a,n-1);
}
void displaySelection(int a[], int n)
{
    cout <<"The array a : " << endl; 
    for(int i = 0; i < n; i++){
        cout << setw(4) << a[i];
    }
}
void swap(int &i, int &j)
{
    int temp;
    temp = i;
    i = j;
    j = temp;

}