初始化链表 ，插入结点，删除结点，返回结点位置 ，遍历链表 。

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

/*链表存储结构的定义*/
typedef struct CLinkList
{
int data;
struct CLinkList *next;
}node;

/************************************************************************/
/* 操作                                                                  */
/************************************************************************/

/*初始化循环链表*/
void ds_init(node **pNode)
{
int item;
node *temp;
node *target;

printf("输入结点的值，输入0完成初始化\n");

while(1)
{
scanf("%d", &item);
//        fflush(stdin);

if(item == 0)
return;

if((*pNode) == NULL)
{ /*循环链表中只有一个结点*/
*pNode = (node*)malloc(sizeof(struct CLinkList));
if(!(*pNode))
exit(0);
(*pNode)->data = item;
(*pNode)->next = *pNode;
}
else
{
/*找到next指向第一个结点的结点*/
for(target = (*pNode); target->next != (*pNode); target = target->next);

/*生成一个新的结点*/
temp = (node *)malloc(sizeof(struct CLinkList));

if(!temp)
exit(0);

temp->data = item;
temp->next = *pNode;
target->next = temp;
}
}
}

/*插入结点*/
/*参数：链表的第一个结点，插入的位置*/
void ds_insert(node **pNode , int i)
{
node *temp;
node *target;
node *p;
int item;
int j = 1;

printf("输入要插入结点的值:");
scanf("%d", &item);

if(i == 1)
{ //新插入的结点作为第一个结点
temp = (node *)malloc(sizeof(struct CLinkList));

if(!temp)
exit(0);

temp ->data = item;

/*寻找到最后一个结点*/
for(target = (*pNode); target->next != (*pNode); target = target->next)
;

temp->next = (*pNode);
target->next = temp;
*pNode = temp;
}
else
{
target = *pNode;

for( ; j < (i-1); ++j )
{
target=target->next;
}

temp = (node *)malloc(sizeof(struct CLinkList));

if(!temp)
exit(0);

temp ->data = item;
p = target->next;
target->next = temp;
temp->next = p;
}
}

/*删除结点*/
void ds_delete(node **pNode, int i)
{
node *target;
node *temp;
int j = 1;

if(i == 1)
{ //删除的是第一个结点
/*找到最后一个结点*/
for(target = *pNode; target->next != *pNode;target = target->next)
;

temp = *pNode;
*pNode = (*pNode)->next;
target->next = *pNode;
free(temp);
}
else
{
target = *pNode;

for( ; j < i-1; ++j )
{
target = target->next;
}

temp = target->next;
target->next = temp->next;
free(temp);
}
}

/*返回结点所在位置*/
int ds_search(node *pNode, int elem)
{
node *target;
int i = 1;

for(target = pNode; target->data != elem && target->next != pNode; ++i)
{
target = target->next;
}

if(target->next == pNode) /*表中不存在该元素*/
return 0;
else
return i;
}

/*遍历*/
void ds_traverse(node *pNode)
{
node *temp;
temp = pNode;
printf("***********链表中的元素******************\n");

do
{
printf("%4d ", temp->data);
}while((temp = temp->next) != pNode);

printf("\n");
}

int main()
{
node *pHead = NULL;
char opp;
int find;

printf("-------------------------------------------------------\n\n");
printf("1.初始化链表 \n\n2.插入结点 \n\n3.删除结点 \n\n4.返回结点位置 \n\n5.遍历链表  \n\n0.退出 \n\n请选择你的操作：");
while(opp != '0')
{
scanf("%c", &opp);
switch(opp)
{
case '1':
ds_init(&pHead);
printf("\n");
ds_traverse(pHead);
break;

case '2':
printf("输入需要插入结点的位置？");
scanf("%d",  &find);
ds_insert(&pHead, find);
printf("在位置%d插入值后：\n",  find);
ds_traverse(pHead);
printf("\n");
break;

case '3':
printf("输入需要删除的结点位置？");
scanf("%d",  &find);
ds_delete(&pHead, find);
printf("删除第%d个结点后:\n",  find);
ds_traverse(pHead);
printf("\n");
break;

case '4':
printf("你要查找倒数第几个结点的值？");
scanf("%d",  &find);
printf("元素%d所在位置：%d\n",  find,  ds_search(pHead, find));
//ListTraverse(L);
printf("\n");
break;

case '5':
ds_traverse(pHead);
printf("\n");
break;

case '0':
exit(0);
}
}

return 0;
}