#include <stdio.h>/* * swap two elements (no pointers) */void npswap(int x, int y){	int temp;		/* temporary */	/*	 * show what they are on entry	 */	printf("begin npswap: elem1 is %d, elem2 is %d\n", x, y);	/*	 * do the swap	 */	temp = x;	x = y;	y = temp;	/*	 * show they were exchanged	 */	printf("  end npswap: elem1 is %d, elem2 is %d\n", x, y);}/* * swap two elements (pointers) */void pswap(int *x, int *y){	int temp;		/* temporary */	/*	 * show what they are on entry	 */	printf("begin  pswap: elem1 is %d, elem2 is %d\n", *x, *y);	/*	 * do the swap	 */	temp = *x;	*x = *y;	*y = temp;	/*	 * show they were exchanged	 */	printf("  end  pswap: elem1 is %d, elem2 is %d\n", *x, *y);} /* * this is to show that everything is call by value * so you need to simulate call by reference * it uses swapping */void main(void){	int elem1 = 4;			/* first element */	int elem2 = 5;			/* second element */	/*	 * say what you're starting with	 */	printf("     initial: elem1 is %d, elem2 is %d\n",								elem1, elem2);	/*	 * use the non-pointer swap and print the results	 */	npswap(elem1, elem2);	printf("after npswap: elem1 is %d, elem2 is %d\n",								elem1, elem2);	/*	 * use the pointer swap and print the results	 */	pswap(&elem1, &elem2);	printf("after  pswap: elem1 is %d, elem2 is %d\n",								elem1, elem2);	/*	 * say goodbye	 */	exit(0);}