/*
 * George Brecht. "TWO EXERCISES," Fall 1961.
 * Arranged for terminal in C by David W. Speck, 2010.
 */

#include <stdio.h>
#include <stdlib.h>

/* TWO EXERCISES */

/* Consider an object. */

typedef struct object {
    int part;
    struct object *object;
} object;

/* Call what is not the object "other." */

int other(int object)
{
    if (object == EOF)
        return getchar();
    else
        return putchar(object);
}

int main(void)
{
    int another;
    object *new;
    object *object = NULL;

    /*
     * EXERCISE: Add to the object, from the "other," another
     *           object, to form a new object and a new "other."
     *
     *           Repeat until there is no more "other."
     */

    while ((another = other(EOF)) != EOF) {
        if ((new = malloc(sizeof(struct object))) == NULL)
            return 1;
        new->part = another;
        new->object = object;
        object = new;
    }

    /*
     * EXERCISE: Take a part from the object and add it to the
     *           "other," to form a new object and a new "other."
     *
     *           Repeat until there is no more object.
     */

    while (object != NULL) {
        if (other(object->part) == EOF)
            return 1;    
        new = object->object;
        free(object);
        object = new;
    }

    return 0;
}