#include <iostream>

using namespace std;

void swap(int n1, int n2) {
  int temp = n1;
  n1 = n2;
  n2 = temp;
  cout << "dans swap: " << n1 << "  " << n2 << endl;
  return;
}

void swap_p(int *n1, int *n2) {
  int temp = *n1;
  *n1 = *n2;
  *n2 = temp;
  cout << "dans swap_p: " << *n1 << "  " << *n2 << endl;
  return;
}

void swap_ref(int &n1, int &n2) {
  int temp = n1;
  n1 = n2;
  n2 = temp;
  cout << "dans swap_ref: " << n1 << "  " << n2 << endl;
  return;
}