linux style circular double linked list implementation. If you fully understand this code, you may pass CS 101 - basic computer programming. In fact it's c language code, but tested using VS2012.

heo-se.cpp

/* heo-se.cpp : win32 console application
   This program prints only one line.
   Yes, that's all.
   Main concept is from include/linux/list.c in linux kernel 2.6.xx.
   Author: Hoyoung Jung, NHN NEXT
   Date: 2012.02.01   
   license: anyone can freely use and modify this code.
*/

#include "stdafx.h"
// these headres are alreay included in stdafx.h
#include <stdio.h>
#include <string.h>

struct list {
  list *prev, *next;	
};

struct letter {
	unsigned int seq;
	char ch;
	list node;
};

#define INIT_LL(name) \
	struct list name = { &(name), &(name)}

inline void _add_list(struct list *node, struct list *head, struct list *next)
{
	node-> next = next;
	node-> prev = head;
	head-> next = node;	
	next-> prev = node;
}

inline void add_first(struct list *node, struct list * head) 
{
	_add_list(node,head, head->next);
}

inline void add_last(struct list *node, struct list * head)
{
	_add_list(node,head->prev,head);
}


#define for_each_node(list, head) \
	for(list = (head)->next; list!=(head); list= list->next)

#define get_struct_from_list(list, type, member) \
	(type *) ((char*)list - (unsigned long) &((type *) 0) ->member)

#define MAX 64

int _tmain(int argc, _TCHAR* argv[])
{
	INIT_LL(head);
	int i;
	struct letter data[MAX];
	//char *stmt = "Hello, NEXT";
	char *stmt = "TXEN, olleH";
	int len = strlen(stmt);
	for (i=0; i < len; i++)
	{
		data[i].seq=i;
		data[i].ch = stmt[i];		
	}

#if 0
	//for test
	for (i=0; i < len; i++)
	{
		if (data[i].seq==i)
		printf("%c" ,data[i].ch);	
	}
	printf("\n");
#endif

	for(i=0; i < len; i++)
	{
		add_first( &data[i].node, &head);
		//add_last(&data[i].node, &head);
	}

	struct list *n;
	struct letter *itr;
	for_each_node (n, &head)
	{
		itr = get_struct_from_list(n,struct letter, node);
		printf("%c",itr->ch);
	}
	printf("\n");
	return 0;
}