数据结构----循环链表

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CycLinkList.h

#ifndef __CYCLINKLIST_H
#define __CYCLINKLIST_H

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

typedef  int ElemType;

typedef struct Node //定义结点
{
	ElemType data;
	struct Node *next;
}Node;

/*
//定义带头结点的链表
typedef struct Linklist
{
	struct Node head;
	int count;
}Linklist, *pList;
*/

//定义不带头结点的链表
typedef struct Linklist
{
	struct Node *head;
	int count;
}Linklist, *pList;

void InitLinkList(pList list);

void InsertLinkList(pList list, ElemType val, int pos);

void InsertHeadLinkList(pList list, ElemType val);

void InsertTailLinkList(pList list, ElemType val);

void DeleteLinkList(pList list, int pos);

void DeleteHeadLinkList(pList list);

void DeleteTailLinkList(pList list);

void ShowLinkLIst1(pList list);
void ShowLinkLIst2(pList list);

#endif

CycLinkList.c

#include"CycLinkList.h"


//不带头结点的循环链表
void  InitLinkList(pList list)//初始化链表
{
	list->count = 0;
	list->head = NULL;
}

static Node *BuyNode(ElemType val, Node *next)
{
	Node *p = ( Node *)malloc(sizeof(Node));
	assert( p != NULL);

	p->data = val;
	if( next == NULL)//考虑链表中没有结点时的情况
	{
		p->next = p;
		return p;
	}
	p->next = next;
	return p;
}

void InsertLinkList(pList list, ElemType val, int pos) //插入结点
{
	if( pos < 0 || pos > list->count)
	{
		printf("pos is error\n");
		return ;
	}

	if(list->head == NULL)//考虑链表中没有结点时的插入
	{
		list->head = BuyNode(val, NULL); //给头结点赋值
		list->count++;
		return;
	}
	Node *p = list->head;
	int tmpos = pos == 0 ? list->count : pos;//若为头插则相当于尾插后前移头指针
	while( tmpos > 1)
	{
		p =p->next;
		tmpos --;
	}
	Node *s = BuyNode(val, p->next);
	p->next = s;
	if(pos == 0) //如果pos为0即为头插,则改变头指针位置
	{
		list->head = s;
	}
	list->count++; //增加结点个数
}

void InsertHeadLinkList(pList list, ElemType val) //头插
{
	InsertLinkList(list, val, 0);
}

void InsertTailLinkList(pList list, ElemType val) //尾插
{
	InsertLinkList(list, val, list->count);
}

void DeleteLinkList(pList list, int pos) //删除结点
{
	assert(list != NULL);
	if(pos < 1 || pos > list->count)
	{
		printf("pos is error\n");
		return ;
	}
	if(list->count == 1)
	{
		free(list->head);
		list->head = NULL;
		list->count--;
	}
	Node *p = list->head;
	if( pos == 1)
	{
		while( p->next != list->head)
		{
			p = p->next;
		}
		list->head = list->head->next;
	}
	else
	{
		while( pos > 2)
		{
			p = p->next;
			pos --;
		}
	}	
		Node *q = p->next;
		p->next = q->next;
		free(q);
		list->count--;
	
}

void DeleteHeadLinkList(pList list)  //头删
{
	DeleteLinkList(list, 1);
}

void DeleteTailLinkList(pList list)  //尾删
{
	DeleteLinkList(list, list->count);
}

void ShowLinkLIst1(pList list)  //输出打印
{
	assert(list != NULL);
	Node *p = list->head;
	while( p->next != list->head)
	{
		printf("%3d",p->data);
		p = p->next;
	}
	printf("%3d\n",p->data);
}

void ShowLinkLIst2(pList list)
{
	assert(list != NULL);
	Node *p = list->head;
	int tmp = list->count;
	while(tmp > 0)
	{
		printf("%3d",p->data);
		p =p->next;
		tmp --;
	}
	printf("\n");
}

main.c

#include "CycLinkLIst.h"

int main()
{
	Linklist list;
	InitLinkList(&list);
	for( int i = 0; i < 5; i++)
	{
		InsertLinkList(&list, i * 10, i);
	}
	ShowLinkLIst1(&list);
	
	for( int j = 3; j > 0; j--)
	{
		DeleteLinkList(&list, j);
		ShowLinkLIst1(&list);
	}
	ShowLinkLIst2(&list);

	return 0;
}