循环链表和单链表其实区别不大,差别仅在于算法中的循环条件不是p或者p->next,而是是否等于头指针。下面这个例子简单的实现了循环链表的基本操作,其中插入和删除只是完成了主要的部分,没有判断。

#include

#include

struct Data

{

char name;

int age;

};

struct CirList

{

Data *data;

CirList *next;

};

CirList* InitListhead()

{

CirList *list;

list = (CirList*)malloc(sizeof(CirList));

list->next = NULL;

return list;

}

CirList *CreateData()

{

CirList *node;

node = (CirList*)malloc(sizeof(CirList));

node->next = NULL;

node->data = (Data*)malloc(sizeof(Data));

printf("输入姓名:");

scanf("%c",&node->data->name);

printf("输入年龄:");

scanf("%d",&node->data->age);

getchar();

return node;

}

//头插法初始化链表

void InitList(CirList *head)

{

CirList *node ;

node = CreateData();

//新结点的next指针域赋给头结点的next指针域

node->next = head->next;

//新结点赋给头结点的指针域

head->next = node;

//新结点指针域指向头结点

node->next = head;

}

//尾插法初始化链表

void InitList_2(CirList *list)

{

CirList *node,*p=list;

int i = 0;

while(i<3)

{

node = CreateData();

p->next = node;

p = node;

i++;

}

//令表尾指针指向头结点

node->next = list;

}

void Insert(CirList *list)

{

CirList *node,*saveHead = list;

node = CreateData();

printf("输入插入位置:");

int position,i=0;

scanf("%d",&position);

//寻找插入的前驱

while(list != NULL && i < position-1)

{

list = list->next;

i++;

}

node->next = list->next;

list->next = node;

}

void Delete(CirList *list)

{

CirList *temp,*saveHead = list;;

printf("输入删除位置:");

int position,i=0;

scanf("%d",&position);

//寻找插入的前驱

while(list != NULL && i < position-1)

{

list = list->next;

i++;

}

temp = list->next;

list->next = temp->next;

free(temp);

}

void Output(CirList *list)

{

CirList *p = list->next;

printf("链表中所有数据如下:\n");

while(p != list)

{

printf("姓名:%c\n",p->data->name);

printf("年龄:%d\n",p->data->age);

p = p->next;

}

}

void menu()

{

printf("*****循环链表练习*****\n");

printf(" * 1---初始化链表\n");

printf(" * 2---删除数据\n");

printf(" * 3---插入数据\n");

printf(" * 4---输出数据\n");

printf(" * 0---退出\n");

printf("********************\n");

}

int main()

{

CirList *list;

list = InitListhead();

int i=0;

printf("初始化数据:\n");

//while(i<3)

{

//InitList(list);

//i++;

}

int choose;

do

{

menu();

printf("输入您的选择:");

scanf("%d",&choose);

getchar();

switch(choose)

{

case 1:

InitList_2(list);

break;

case 2:

Delete(list);

break;

case 3:

Insert(list);

break;

case 4:

Output(list);

break;

}

}while(choose !=0);

return 0;

}