Question

10.16 LAB: Grocery shopping list (linked list: inserting at the end of a list)

Hello, I searched for similar problems, but their InsertAtEnd() have two parameters, while my question asks for one.

Given main(), define an InsertAtEnd() member function in the ItemNode class that adds an element to the end of a linked list.DO NOT print the dummy head node.

Ex. if the input is:

4
Kale 
Lettuce 
Carrots 
Peanuts

where 4 is the number of items to be inserted; Kale, Lettuce, Carrots, Peanuts are the names of the items to be added at the end of the list.

The output is:

Kale 
Lettuce 
Carrots 
Peanuts

//ItemNode.h

---------------------------------------------------------------------------------

#include
#include
using namespace std;

class ItemNode {
private:
   string item;
   ItemNode* nextNodeRef;

public:
   // Constructor
   ItemNode() {
       item = "";
       nextNodeRef = NULL;
   }

   // Constructor   
   ItemNode(string itemInit) {
       this->item = itemInit;
       this->nextNodeRef = NULL;
   }

   // Constructor
ItemNode(string itemInit, ItemNode *nextLoc) {
this->item = itemInit;
this->nextNodeRef = nextLoc;
}

   // Insert node after this node.   
void InsertAfter(ItemNode &nodeLoc) {
ItemNode* tmpNext;
tmpNext = this->nextNodeRef;
this->nextNodeRef = &nodeLoc;
nodeLoc.nextNodeRef = tmpNext;
}
  
   // TODO: Define insertAtEnd() function that inserts a node
   // to the end of the linked list
void InsertAtEnd(ItemNode *currNode){
ItemNode * headNode;
if(currNode == NULL){ // check if it is the first Node
headNode = currNode; // add curr to head
}else{ // find last node
while(headNode->nextNodeRef!=NULL){
headNode = headNode->nextNodeRef;
}// add currnode to last node
headNode->nextNodeRef = currNode;
}
}

   // Get location pointed by nextNodeRef   
   ItemNode* GetNext() {
       return this->nextNodeRef;
   }

   void PrintNodeData() {
       cout << this->item << endl;
   }
};

---------------------------------------------------------------------------------

#include "ItemNode.h"

int main() {
   ItemNode *headNode; // Create intNode objects   
   ItemNode *currNode;
   ItemNode *lastNode;

   string item;
   int i;
   int input;

   // Front of nodes list   
   headNode = new ItemNode();
   lastNode = headNode;

   cin >> input;

   for (i = 0; i < input; i++) {
       cin >> item;
       currNode = new ItemNode(item);
       lastNode->InsertAtEnd(currNode);
       lastNode = currNode;
   }

   // Print linked list   
   currNode = headNode->GetNext();
   while (currNode != NULL) {
       currNode->PrintNodeData();
       currNode = currNode->GetNext();
   }
}

Answer 1

To meet your requirment I have changed in two place.

1. In main method.

2. In InsertAtEnd method

#include 
#include 

using namespace std;

class ItemNode
{
private:
    string item;
    ItemNode *nextNodeRef;

public:
    // Constructor
    ItemNode()
    {
        item = "";
        nextNodeRef = NULL;
    }

    // Constructor
    ItemNode(string itemInit)
    {
        this->item = itemInit;
        this->nextNodeRef = NULL;
    }

    // Constructor
    ItemNode(string itemInit, ItemNode *nextLoc)
    {
        this->item = itemInit;
        this->nextNodeRef = nextLoc;
    }

    // Insert node after this node.
    void InsertAfter(ItemNode &nodeLoc)
    {
        ItemNode *tmpNext;
        tmpNext = this->nextNodeRef;
        this->nextNodeRef = &nodeLoc;
        nodeLoc.nextNodeRef = tmpNext;
    }

    // TODO: Define insertAtEnd() function that inserts a node
    // to the end of the linked list
    void InsertAtEnd(ItemNode *lastNode)
    {
        if (nextNodeRef == NULL)
        {
            nextNodeRef = lastNode;
        }
        else
        {
            ItemNode *secondLast = nextNodeRef;

            while (secondLast->nextNodeRef != NULL)
            {
                secondLast->PrintNodeData();
                secondLast = secondLast->nextNodeRef;
            } // add currnode to last node
            secondLast->nextNodeRef = lastNode;
        }
    }

    // Get location pointed by nextNodeRef
    ItemNode *GetNext()
    {
        return this->nextNodeRef;
    }

    void PrintNodeData()
    {
        cout << this->item << endl;
    }
};

int main()
{
    ItemNode *headNode; // Create intNode objects
    ItemNode *currNode;

    string item;
    int i;
    int input;

    cout << "Enter Number of item :";

    cin >> input;

    for (i = 0; i < input; i++)
    {
        cout << "Enter Item : ";
        cin >> item;

        currNode = new ItemNode(item);
        if (i == 0)
        {
            headNode = currNode;
        }
        else
        {
            headNode->InsertAtEnd(currNode);
        }
    }

    // Print linked list
    currNode = headNode;
    while (currNode != NULL)
    {
        currNode->PrintNodeData();
        currNode = currNode->GetNext();
    }
}

past this code in single file and complie and run.

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if you have any query, ask in comment.

Regards.