#include <stdio.h>

void swap(int *pa, int *pb)
{
	int t = *pa;
	*pa = *pb;
	*pb = t;
}

int main()
{
	int x = 3, y = 4;
	int *a, *b;

	printf("x = %d, y = %d\n", x, y);

	//swap(&x, &y);	// equivalent to the next three lines
	a = &x;
	b = &y;
	swap(a, b);

	printf("x = %d, y = %d\n", x, y);
}