/****************************************************************************
 * swap.c
 *
 * Computer Science 50
 * David J. Malan
 *
 * Swaps two variables' values.
 *
 * Demonstrates passing by reference.
 ***************************************************************************/
       
#include <stdio.h>


// function prototype 
void swap(int *, int *);


int
main(int argc, char *argv[])
{
    int x = 1;
    int y = 2;

    printf("x is %d\n", x);
    printf("y is %d\n", y);
    printf("Swapping...\n");
    swap(&x, &y);
    printf("Swapped!\n");
    printf("x is %d\n", x);
    printf("y is %d\n", y);
}


/*
 * void
 * swap(int *a, int *b)
 *
 * Swap arguments' values.
 */

void
swap(int *a, int *b)
{
    int tmp;

    tmp = *a;
    *a = *b;
    *b = tmp;
}