# include "stdio.h"
void main( )               
{ int a=101,b=505,*pa=&a,*pb=&b;
 printf("a=%d, b=%d",a,b);
 chang(pa,pb);
printf("a=%d, b=%d",a,b);
chang(&a,&b);
printf("a=%d, b=%d",a,b);
}
 chang(p1,p2)
int *p1,*p2;
{
int temp;
 temp=*p1;
  *p1=*p2;
  *p2=temp;
}