Question

C++ LinkedList I need the code for copy constructor and assignment operator

#include <iostream>
#include <string>
using namespace std;

typedef string ItemType;

struct Node {
   ItemType value;
   Node *next;
};

class LinkedList {
private:
   Node *head;
   // You may add whatever private data members or private member functions you want to this class.
   void printReverseRecursiveHelper(Node *temp) const;
public:
   // default constructor
   LinkedList() : head(nullptr) { }

   // copy constructor
   LinkedList(const LinkedList& rhs);

   // Destroys all the dynamically allocated memory
   // in the list.
   ~LinkedList();

   // assignment operator
   const LinkedList& operator=(const LinkedList& rhs);

   // Inserts val at the rear of the list
   void insertToRear(const ItemType &val);

   // Prints the LinkedList
   void printList() const;

   // Sets item to the value at position i in this
   // LinkedList and return true, returns false if
   // there is no element i
   bool get(int i, ItemType& item) const;

   // Reverses the LinkedList
   void reverseList();

   // Prints the LinkedList in reverse order
   void printReverse() const;

   // Appends the values of other onto the end of this
   // LinkedList.
   void append(const LinkedList &other);

   // Exchange the contents of this LinkedList with the other
   // one.
   void swap(LinkedList &other);

   // Returns the number of items in the Linked List.
   int size() const;

};

Answer 1

LinkedList::LinkedList(const LinkedList& rhs)

{

    // if th elist rhs is empty

    if( rhs == NULL || rhs.head == NULL )

    {

        this->head = NULL;

        return;

    }

   

    // allocate memory to the node

    this->head = ( struct Node * )malloc( sizeof( struct Node ) );

   

    // set the value of the head node

    this->head->value = rhs.head.value;

   

    // point trav1 to the current list

    struct Node *trav1 = this->head;

   

    // point trav2 to the list rhs

    struct Node *trav2 = rhs.head.next;

   

    // trav the list

    while( trav2 != NULL )

    {

        // allocate memory to the node

        struct Node *new_node = ( struct Node * )malloc( sizeof( struct Node ) );

       

        // set the value of the head node

        new_node->value = trav2.value;

       

        // make the trav1 node point to the new node so

        // that we add this node to the current list

        trav1->next = new_node;

        

        // go to next node

        trav2 = trav2->next;

    }

   

    trav1->nxt = NULL;

}

const LinkedList& operator=(const LinkedList& rhs)

{

    LinkedList ob;

   

    // if the list rhs is empty

    if( rhs == NULL || rhs.head == NULL )

    {

        ob.head = NULL;

        return;

    }

   

    // allocate memory to the node

    ob.head = ( struct Node * )malloc( sizeof( struct Node ) );

   

    // set the value of the head node

    ob.head->value = rhs.head.value;

   

    // point trav1 to the current list

    struct Node *trav1 = ob.head;

   

    // point trav2 to the list rhs

    struct Node *trav2 = rhs.head.next;

   

    // trav the list

    while( trav2 != NULL )

    {

        // allocate memory to the node

        struct Node *new_node = ( struct Node * )malloc( sizeof( struct Node ) );

       

        // set the value of the head node

        new_node->value = trav2.value;

       

        // make the trav1 node point to the new node so

        // that we add this node to the current list

        trav1->next = new_node;

       

        // go to next node

        trav2 = trav2->next;

    }

   

    trav1->nxt = NULL;

   

    return ob;

}