Link list using C++ improved version 2021

 Link list using C++ improved version 2021

source code:

#include<iostream>

using namespace std;

class Node 

{ 

private: 

 int object; 

 Node * nextNode;//address of next node 

public: 

 int get() { return object; }; 

 void set(int object) { this->object = object; }; 

 Node * getNext() { return nextNode; }; 

 void setNext(Node * nextNode) { this->nextNode = nextNode; }; 

};

////////////////////list class//////////////////

/* The List class */ 

class List 

{ 

public://methods or function 

//declare the functions

 List(); //constructor

 void add (int addObject); //add new object

 int get(); //get node

 bool next(); 

 friend void traverse(List list); 

 friend List addNodes(); //add new node

 ////

 // position currentNode and lastCurrentNode at first element 

void start()

 { ////headNode currentNode lastCurrentNode

 lastCurrentNode = headNode; 

 currentNode = headNode; 

} 

////////////

void remove() 

{ 

 if( currentNode != NULL && currentNode != headNode)

  { 

lastCurrentNode->setNext(currentNode->getNext()); //(step 1) 

 delete currentNode; //(step 2)

currentNode = lastCurrentNode;//(step 3)  

size--; //(step 4) 

 } 

}

 ////

 // returns the size of the list 

int length() 

{ 

 return size; 

}

 

 

 

 

 

private: //data members

 int size; 

 Node * headNode; 

 Node * currentNode; 

 Node * lastCurrentNode; 

};//end of class 

/* Constructor */ 

//define the function: work

List::List() 

{ 

headNode = new Node(); 

 headNode->setNext(NULL); 

 currentNode = NULL; 

 lastCurrentNode = NULL; 

 size = 0; 

}

/* add() class method */ 

void List::add (int addObject) 

{ 

 Node * newNode = new Node(); 

 newNode->set(addObject); 

 if( currentNode != NULL ) 

 { 

 newNode->setNext(currentNode->getNext()); 

 currentNode->setNext( newNode ); 

 lastCurrentNode = currentNode; 

 currentNode = newNode; 

 } 

 else //when currentNode == NULL

 {newNode->setNext(NULL); 

 headNode->setNext(newNode); 

 lastCurrentNode = headNode; 

 currentNode = newNode; 

 } 

 size ++; 

} 

/* get() class method */ 

int List::get() 

{ 

 if (currentNode != NULL) 

 return currentNode->get(); 

} 

/* next() class method */ 

bool List::next() 

{ 

 if (currentNode == NULL) return false; 

 lastCurrentNode = currentNode; 

 currentNode = currentNode->getNext(); 

 if (currentNode == NULL || size == 0) 

return false; 

 else 

 return true;

 } 

/* Friend function to traverse linked list */ 

void traverse(List list) 

{ //show the elements

 Node* savedCurrentNode = list.currentNode; 

 list.currentNode = list.headNode; 

 

 for(int i = 1; list.next(); i++) 

 { 

 cout << "\n Lists Element " << i << " :" << list.get(); 

 } 

 list.currentNode = savedCurrentNode; 

}

/* Friend function to add Nodes into the list */ 

List addNodes() 

{ 

 List list; //create a simple object

 list.add(2); 

 list.add(6); 

 list.add(8); 

 list.add(7); 

 list.add(1); 

 

 //List *p;//pointer type object

 //p->add(5);

 cout << "\n List size = " << list.size <<'\n'; 

 return list; 

} 

main() 

{ 

// List list = addNodes(); 

 //traverse(list); 

 cout << "\n ******** Link List C++ Example ********" <<'\n'; 

 List list; // creating a list object 

 

 // adding values to the list 

 list.add(10); 

 list.add(11); 

 list.add(12); 

 list.add(13); 

 list.add(14); 

 list.add(15); 

 list.add(16); 

 // calling the start method of the list 

 list.start(); 

 // printing all the elements of the list 

 while (list.next()) 

 cout << "Elements of list container : "<< list.get()<<endl;

 

  cout << "\n ********** By  Hafiz Muhammad Umar Hayat ******** : "<< list.get()<<endl;

system("pause");

}

****************Result****************