/*
 * Stack implementation methods.
 */

#include "intstack.h"

// Remove from the stack.
int IntStack::pop() {
	if (head != NULL) {
		// Unlink the top node.
		StackNode *oldtop = head;
		head = head->next;

		// Get the data out of it, and destroy it.
		int retval = oldtop->data;
		delete oldtop;

		// Return the top value.
		return retval;
	} else
		return 0;
}

// Remove all memory from the stack.
void IntStack::clear() {
	while(head != NULL) {
		// Advance the pointer and delete the old node.
		StackNode *zombie = head;
		head = head->next;
		delete head;
	}
	head = NULL;
}