循环单行插入，添加新节点并替换它

Question

Neither of the compilers I've used are able to debug it. I am trying to add a new node at the end of the list and then displaying it,,, they are not showing any sort of errors , both give a send dont send error by windows , I think this may be a memory leak..Please help me

#include <iostream>
#include <conio.h>
using namespace std;

struct Node
{
    int data;
    Node *nextptr;
};


class CLLIST{

private:
    Node*firstptr;
    Node*lastptr;

public:
     CLLIST(){

     cout << "Constructor Called !";
      firstptr=lastptr=NULL;
}

 void insert_at_back(int val){
     cout << " \n \n I am in the insert at back function: ";
     Node*newptr;
     newptr = new Node;
     newptr->data=val;

     if(firstptr=NULL)//means list is empty
     {
         firstptr=newptr;

     }else{
         lastptr->nextptr=newptr;
     }

     lastptr=newptr;
     lastptr->nextptr=firstptr;
 }

 void display(){

     Node *temptr,*endptr;
     temptr = new Node;
     endptr = new Node;

     temptr=firstptr;
     endptr = NULL;
     while(temptr!=endptr){

         cout << "I am in the display Function: ";
         cout << firstptr->data << " ";
         firstptr=firstptr->nextptr;
         endptr=firstptr;}

         delete temptr;
         delete endptr;
     }


 };





 int main()
 {
 CLLIST obj1;




  obj1.insert_at_back(26);

  obj1.display();

 cout << " \n \n Done !";

getch();
 }

Answer 1

temptr=firstptr; endptr = NULL; while(temptr!=endptr){

     cout << "I am in the display Function: ";
     cout << firstptr->data << " ";
     firstptr=firstptr->nextptr;
     endptr=firstptr;}

     delete temptr;
     delete endptr;
 }

you are comparing tempptr with endptr in the while condition, but you never reassign the tempptr because in the beggining tempptr = firstptr, and then firstptr cycles through list and then you assign endptr = firstptr, this means that tempptr will always be equal to firstptr and endptr and condition temptr!=endptr will never fail

instead of

firstptr=firstptr->nextptr;

use

tempptr = tempptr->nextptr;

also you can use the do { } while() statement and initilize endptr in the begginng