#include <stdio.h>

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

main(int argc, char ** argv)
{  int x,y;
   x = 1;
   y = 2;
   swap(&x,&y);
   printf("x: %d, y: %d\n",x,y);
}