链表 文件 操作

#include<iostream> 
#include<fstream>
#include<sstream>
#include<string>
using namespace std;
typedef struct LNode
{
    string no;
    string name;
    float score;
    struct  LNode *next;
}LNode;


LNode *inputlist()
{
   LNode *p,*tail;
   LNode *head=new LNode;
   head->next=NULL; 
   string line;
   string no,name;
   int h=0;
   float score;
   ifstream ifs("1.txt");
   if(!ifs)
   {
   cout<<"寻找不到指定文件"<<endl;
   exit(0);
   }
   while(getline(ifs,line))

   {
   istringstream is(line);
   if(h==0)
   {
   h=1;
   continue;
   }
   p=new LNode;
   is>>no>>name>>score;
   p->no=no;
   p->name=name;
   p->score=score;
   p->next=NULL;
   if(head->next==NULL)
   head->next=p; //增加头结点
   else
   tail->next=p; //在表尾进行数据的插入
   tail=p;
   }  
   ifs.close();
   return head;
} 

/*
  *p 应该是表头的指针
*/
void add(LNode *p)           
{
string no,name;
float score;