/* Example 14.1: Using pointers
	Source: K&R2, p95-96
	Modified by Peter Brusilovsky
	Objective: use of addresses in function arguments
	*/
	#include <stdio.h>
	void bad_swap(int x, int y);
	void good_swap(int *p1, int *p2);
	main() {
	int a = 1, b = 999;
	printf("a = %d, b = %d ", a, b);
	bad_swap(a, b);
	printf("a = %d, b = %d ", a, b);
	good_swap(&a, &b)
	printf("a = %d, b = %d ", a, b)
	}
	/* bad example of swapping - a function can't change parameters */
	void bad_swap(int x, int y) {
	int temp;
	temp = x;
	x = y;
	y = temp;
	}
	/* good example of swapping - a function can't change prameters
	but if a parameter is a pointer it can change the value it points to */
	void good_swap(int *px, int *py) {
	int temp;
	temp = *px;
	*px = *py;
	*py = temp;
	}