/* okswap.c */
#include <stdio.h>
void swap(int *a, int *b);

main()
{
  int x, y;
  x = 12;
  y = 24;
  printf("x = %d  y = %d\n", x, y);
  swap(&x, &y);
  printf("x = %d  y = %d\n", x, y);
}

void swap(int *a,int *b) 
{
  int temp;
  temp = *a;
  *a = *b;
  *b = temp;
}