#include <stdio.h>

void swap (int *, int *);

int main (void)

{
   int a, b;

   printf ("input 2 numeri interi: ");
   scanf ("%d%d", &a, &b);
   printf ("%d %d\n", a, b);

   swap (&a, &b);
   printf ("%d %d\n", a, b);
   return 0;

}

void swap (int *p, int *q)
{
   int tmp;
   tmp = *p;
   *p = *q;
   *q = tmp;
}