//pop.c
//John T. Rine
//October 13, 2011

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

int pop(node **head, node **tail)
{
	int data = 0;
	node *temp = NULL;
	temp = *tail;
	if(*head != NULL && *tail != NULL)
	{
		if (temp == *head)
		{
			temp->next = NULL;
			data = temp->data;
			free(temp);
			*head = *tail = NULL;
		}
		else
		{
			temp->prev->next = NULL;
			*tail = temp->prev;
			temp->prev = NULL;
			data = temp->data;
			free(temp);
		}
	}
	else
	{
		printf("No stack to pop...\n");
		exit(1);
	}
	return data;
}