#include 
    
     #define P pair
     
      using namespace std;typedef long long LL;typedef struct LNode{    int data;    struct LNode *nxt;}LNode,*LinkList;bool Linklist_init(LinkList &root){    root = new LNode; ///分配头结点，指针域为空，下一个结点才是第一个结点    root->nxt = NULL;    return true;}/**查找链表中第k个元素(k下标从1开始)*/int Find_by_location(LinkList root,int k){    LinkList now = root->nxt;    if(!k) return -1;    int cnt = 1;    while(now && cnt < k){        now = now->nxt,cnt++;    }    if(!now) return -1;///第k个元素不存在    return now->data;}int Find_by_value(LinkList root,int value){    LinkList now = root->nxt;    while(now && now->data != value) now = now->nxt;    if(now) return 1;///找到了    return -1;///找不到}/**头插法*/bool Insert(LinkList &root,int value){    LinkList now = new LNode;    now->data = value;    now->nxt = root->nxt;    root->nxt = now;    return true;}/**在第pos - 1 和 第pos个元素之间插入数据*/bool Insert_by_location(LinkList root,int pos,int value){    if(!pos) return false;    int cnt = 0;    while(root && cnt < pos -1){        cnt++,root = root->nxt;    }    if(!root) return false;    LinkList now = new LNode;    now->data = value;    now->nxt = root->nxt;    root->nxt = now;    return true;}/**删除第pos个元素*/bool Delete_by_location(LinkList root,int pos){    if(!pos) return false;    int cnt = 0;    while(cnt < pos - 1) cnt++,root = root->nxt;    if(!root) return false;    LinkList tmp = root->nxt;    root->nxt = tmp->nxt;    delete tmp;    tmp = NULL;    return true;}void rep_print(LinkList root){    root = root->nxt;    for(;root;root = root->nxt) printf("%d ",root->data);    printf("\n");}int main(void){   LinkList root;   Linklist_init(root);   for(int i = 1;i <= 10;i++) Insert(root,i);   rep_print(root);   Insert_by_location(root,3,15);   Insert_by_location(root,4,16);   rep_print(root);   Delete_by_location(root,5);   rep_print(root);   return 0;}