C Program to swap memory address by using pointers

main()
{
 int a, b, *p1, *p2, x, y, z;
 clrscr();
 a=10;
 b= 5;
 p1=&a;
 p2=&b;
 x= *p1 * *p2 -6;
 y= 4 * - *p1 / *p2 + 10;
 printf("Address of a: %u\n",p1);
 printf("Address of b: %u\n",p2);
 printf("\na: %d, b: %d\n",a,b);
 printf("X: %d, y: %d\n",x,y);
 *p2=*p2+3;
 *p1=*p2-5;
 z= *p1 * *p2-6;
 printf("\na: %d, b: %d",a,b);
 printf("\nz: %d", z);
 getch();
}