数据结构之链式表的实现--单向循环链表(C语言)

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 学习参考: 严蔚敏: 《数据结构-C语言版》

单向循环链表的基本操作

1. 单向循环链表的建立
2. 单向循环链表添加结点(头插法)
3. 单向循环链表添加结点(尾插法)
4. 单向循环链表的输出
5. 单向循环链表的修改
6. 单向循环链表的插入
7. 单向循环链表的删除
8. 单向循环链表按序号查找
9. 单向循环链表按值查找 
10. 单向循环链表销毁
11. 求单向循环链表的长度

基本操作代码实现

单向循环链表的结点定义

typedef struct node
{
	struct node* next;  // 指向下一个结点的指针域
	int data;			// 该结点的数据
}*pNode, Node;

单向循环链表的定义

typedef struct 
{
	pNode node;			// 指向头节点的指针域
	int len;			// 单向循环链表的长度
}*pCirList, CirList;

单向循环链表的建立

int initList(pCirList list)
{
	if(!list)
		return 0;
	list->node = NULL;
	list->len = 0;
	return 1;
}

单向循环链表添加结点(尾插法)

int addDataHead(pCirList list, int data)
{
	pNode p = NULL, q = NULL;
	int count = 1;
	if(!list)
		return 0;
	p = list->node;
	while( count<list->len)
	{
		count++;
		p=p->next;
	}
	q = (pNode)malloc(sizeof(Node));
	q->data = data;
	if( count > list->len && !p)
		q->next = q;
	else
	{
		q->next = list->node;
		p->next = q;
	}
	list->node = q;
	list->len++;
	return 0;
}

单向循环链表添加结点(尾插法)

int addDataTial(pCirList list, int data)
{
	pNode q = NULL, p = NULL;
	int count = 1;
	if(!list)
		return 0;
	p = list->node;
	while( count++<list->len)
		p = p->next;
	q = (pNode)malloc(sizeof(Node));
	q->data = data;
	if(!p)
	{
		list->node = q;
		q->next = q;
	}
	else
	{
		q->next = p->next;
		p->next = q;
	}
	list->len ++;
	return 1;
}

单向循环链表的输出

int display(pCirList list)
{
	pNode p = NULL;
	int count = 0;
	if(!list || !list->node)
		return 0;
	p = list->node;
	while( count<list->len)
	{
		count++;
		printf("%d  ", p->data);
		p = p->next;
	}
	printf("\n");
	return 1;
}

单向循环链表的修改

int updata(pCirList list, int pos, int data)
{
	pNode p = NULL;
	int count = 1;
	if(!list || !list->node || pos<1 || pos>list->len)
		return 0;
	p = list->node;
	while( count<pos)
	{
		
		count++;
		p = p->next;
	}
	p->data = data;
	return 1;		
}

单向循环链表的插入

int insertData(pCirList list, int pos, int data)
{
	pNode pre = NULL, p = NULL;
	int count = 1;
	if(!list  || pos<1 || pos>list->len+1)
		return 0;
	p = list->node;
	while ( count<pos)
	{
		pre = p;
		p = p->next;
		++count;
	}
	if(count == 1 || pos == list->len)
		addDataTial(list,data);
	else
	{
		p = (pNode)malloc(sizeof(Node));
		p->next = pre->next;
		p->data = data;
		pre->next = p;
		list->len ++;
	}
	return 1;
}

单向循环链表的删除

int deleteData(pCirList list, int pos, int* e)
{
	pNode pre = NULL, p = NULL;
	int count = 1;
	if(!list || !list->node || pos<1 || pos>list->len+1)
		return 0;
	p = list->node;
	if(pos==1)
	{
		while (count<list->len)
		{
			count++;
			p = p->next;
		}
		pre = p->next;
		list->node = pre->next;
		p->next = list->node;
		*e = pre->data;
		free(pre);
		pre = NULL;
	}
	else
	{
		while ( count<pos)
		{
			pre = p;
			p = p->next;
			count++;
		} 
		pre->next = p->next;
		*e = p->data;
		free(p);		
		p = NULL;
	}
	list->len --;
	return 1;
}

单向循环链表按序号查找

int getData(pCirList list, int pos, int* data)
{
	pNode p = NULL;
	int count = 1;
	if(!list || !list->node || pos<1 || pos>list->len)
		return 0;
	p = list->node;
	while(count<pos)
	{
		p = p->next;
		count++;
	}
	*data = p->data;
	return 0;
}

单向循环链表按值查找 

int getLocate(pCirList list, int data, int* index)
{	
	pNode p = NULL;
	int count = 1;
	if(!list || !list->node)
		return 0;
	p = list->node;
	while( count<list->len)
	{
		if(p->data==data)
			break;
		p = p->next;
		count++;
	}
	if(count == list->len)
		*index = -1;
	else
		*index = count;
	return 1;
}

单向循环链表销毁

int destroy(pCirList list)
{	
	pNode q = NULL, p = NULL;
	int count = 0;
	if(!list || !list->node)
		return 0;
	p = list->node;
	while(count<list->len)
	{
		q = p;
		p = p->next;
		count++;
		free(q);
		q = NULL;
	}
	list->node = NULL;
	list->len = 0;
	return 0;
}

求单向循环链表的长

int getLength(pCirList list,int* len)
{
	if(!list)
		return 0;
	*len = list->len;
	return 1;
}

测试代码

#include <stdio.h>
#include "CircularList.h"
int main()
{
	int i=1;
	int val = -1;
	CirList list;
	initList(&list);
/*	addDataHead(&list, 1);
	addDataHead(&list, 2);
	addDataTial(&list, 3);
	addDataTial(&list, 4);
	display(&list);
	updata(&list, 1, 1);
	display(&list);
	updata(&list, 2, 2);
	display(&list);*/
	for(i; i<11; ++i)
		insertData(&list, i, i);
	display(&list);
	deleteData(&list, 5, &val);
	printf("%d  \n", val);
	getData(&list, 8, &val);
	getLocate(&list, 1, &val);
	printf("%d  \n", val);
	destroy(&list);
	display(&list);
	return 0;
}