/*
 *  雙向迴圈連結串列的建立及操作
 *  2018.10.23
 *  @L.F
 *
 * */

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

typedef int Datatype;
typedef struct Node
{
	Datatype Data;
	struct Node *Prior;
	struct Node *Next;
}DoubList;

DoubList *DoubListCreate()//定義空的迴圈連結串列
{
	DoubList *h = (DoubList *)malloc(sizeof(DoubList));
	h->Prior = h;
	h->Next  = h;
	return h;
}

void DoubListInsert(DoubList *h, Datatype Value)//插入資料
{
	DoubList *Temp = (DoubList *)malloc(sizeof(DoubList));
	Temp->Data = Value;
	DoubList *Pnext = h->Next;
	Temp->Next = Pnext;
	Pnext->Prior = Temp ;
	h->Next = Temp;
	Temp->Prior = h;
	return ;
}

int DoubListInsertPos(DoubList *h,int pos,Datatype Value)//按照位置插入
{
	int j =0;
	DoubList *p, *s;
	p = h;
	while(j<pos &&p->Next != h)
	{
		p = p->Next;
		j++;
	}
	if(j !=  pos-1)
		return 0;
	p =p->Next;
	s=(DoubList *)malloc(sizeof(DoubList));
	s->Data = Value;
	s->Prior = p->Prior;
	p->Prior->Next = s;
	s->Next = p;
	p->Prior = s;
	return 0;
}

int DoubListDelete(DoubList *h, int pos)//按照位置刪除結點
{
	int j =0;
	DoubList *p;
	p = h;
	while(j < pos &&p->Next != h)
	{
		p =p->Next;
		j++;
	}
	if(j != pos || pos == 0)
		return 0;
	p->Prior->Next = p->Next;
	p->Next->Prior = p->Prior;
	return 0;
}
void DoubListShow(DoubList *h)
{
	DoubList *p = h;
	while(h->Next != p)
	{
		h = h->Next;
		printf("%d ", h->Data);
	}
	putchar(10);
	h = p;
	while(h->Prior != p)
	{
		h = h->Prior;
		printf("%d ", h->Data);
	}
	putchar(10);
	return ;
}
int main(int argc, const char *argv[])
{
	DoubList *h = DoubListCreate();
	
	printf("-------------------------------\n");
	DoubListInsert(h,10);
	printf("-------------------------------\n");
	DoubListInsert(h,20);
	printf("-------------------------------\n");
	DoubListShow(h);
	printf("-------------------------------\n");
    DoubListDelete(h,1);
	DoubListShow(h);
	DoubListInsertPos(h,3,90);
	DoubListInsertPos(h,4,80);
	DoubListInsertPos(h,5,70);
	DoubListInsertPos(h,6,60);
	DoubListInsertPos(h,7,50);
	DoubListInsertPos(h,8,40);
	DoubListShow(h);
	return 0;
}