Vấn đề về this->head=this->head->Getpointer();

[vole565 (Sầu Vô Lệ)]

Mn ơi , em vẫn không hiểu rõ tại sao dòng p=p->Getpointer(); hay dòng this->head=this->head->Getpointer(); trong file linkedlist.cpp là để con trỏ tiến đến phần tử tiếp theo , mn chỉ em với, em cảm ơn !!!

main.cpp

#include <iostream>
#include "linkedlist.h"
using namespace std;
int main()
{
    linkedlist *list_=new linkedlist();
    element *e;
    e=new element(9);
    list_->InsertTail(e);
    e=new element(10);
    list_->InsertTail(e);
    e=new element(8);
    list_->InsertTail(e);
    list_->Travel();
    list_->DeleteFirst();
    cout<<"\n";
    list_->Travel();
    return 0;
}

element.h

#ifndef ELEMENT_H
#define ELEMENT_H
class element
{
    private:
        int data;
        element *pointer;
    public:
        element();
        element(int);
        virtual ~element();
        int Getdata() { return data; }
        void Setdata(int val) { data = val; }
        element * Getpointer() { return pointer; }
        void Setpointer(element* val) { pointer = val; }
    protected:
};
#endif // ELEMENT_H

element.cpp

#include "element.h"
element::element()
{
    //ctor
    this->data=0;
    this->pointer=nullptr;
}
element::element(int data)
{
    //ctor
    this->data=data;
    this->pointer=nullptr;
}
element::~element()
{
    //dtor
} 

linkedlist.h

#ifndef LINKEDLIST_H
#define LINKEDLIST_H
#include "element.h"
class linkedlist
{
    private:
        element* head;
        element* tail;
        int nNum;
    public:
        linkedlist();
        virtual ~linkedlist();
        element* Gethead() { return head; }
        void Sethead(element* val) { head = val; }
        element* Gettail() { return tail; }
        void Settail(element* val) { tail = val; }
        void InsertFirst(element*);
        void InsertTail(element*);
        bool DeleteFirst();
        void Travel();
    protected:
};
#endif // LINKEDLIST_H

linkedlist.cpp

#include "linkedlist.h"
#include <iostream>
using namespace std;
linkedlist::linkedlist()
{
  //ctor
  this->head=nullptr;
  this->tail=nullptr;
  this->nNum=0;
}
linkedlist::~linkedlist()
{
  //dtor
}
void linkedlist::InsertFirst(element* e){
    if(this->head==nullptr)
      this->head=this->tail=e;
      else{
          e->Setpointer(this->head); //step 1
          this->head=e;  // step 2
      }
     this->nNum++;
}
void linkedlist::InsertTail(element*e){
   if(this->head==nullptr)
      this->head=this->tail=e;
      else{
          this->tail->Setpointer(e);// step 1
          this->tail=e;    // step 2
      }
   this->nNum++;
}
void linkedlist::Travel(){
   element* p=this->head;
   while(p!=nullptr){
      cout<<p->Getdata()<<"\t";
      p=p->Getpointer();
   }
}
bool linkedlist::DeleteFirst(){
    if(this->head==nullptr) return false;
    else{
    element*p=this->head;
    this->head=this->head->Getpointer();
    delete p;
    return true;
    }
}

[nguy4nkjn (Nguyen Khasnh)]

Thường thì mình sẽ đặt tên cho pointer ở lớp element là next cho đỡ nhầm lẫn.

[nitro2 (Nhím)]

Find & Replace all files: “pointer” thành “nextElement” là tự nhiên hiểu ngang