手写代码：循环链表插入元素?

参考回答：

typedef struct _tag_CircleListNode{struct _tag_CircleListNode * next;}CircleListNode;typedef struct _tag_CircleList{CircleListNode header;CircleListNode* slider;int length;}TCircleList;

//插入元素

int CircleList_insert(CircleList* list, CireListNode* node, int pos){int ret = 0, i=0;TCircleList* sList = (TCircleList*)list;if (list == NULL || node== NULL || pos<0){return -1;}CircleListNode* current = (CircleListNode*)sList;for(i=0; (i<pos) && (current->next != NULL); i++){current = current->next;}

//current->next 0号节点的地址

node->next = current->next; //1current->next = node; //2

//若第一次插入节点

if( sList->length == 0 ){sList->slider = node;}sList->length++;

//若头插法 current仍然指向头部

//（原因是：跳0步，没有跳走） 中间第一种情况

if( current == (CircleListNode*)sList ){//获取最后一个元素CircleListNode* last = CircleList_Get(sList, sList->length - 1);last->next = current->next; //3}return ret;}CircleListNode* CircleList_Get(CircleList* list, int pos) // O(n){TCircleList* sList = (TCircleList*)list;CircleListNode* ret = NULL;int i = 0;if (list==NULL || pos<0){return NULL;}{CircleListNode* current = (CircleListNode*)sList;for(i=0; i<pos; i++){current = current->next;}ret = current->next;}return ret;}