Answer to Question #188344 in C++ for Araceli Cardenas

Question

Data should be read from a file using a comma delimited format

Use a linked list to store the Course schedule while in memory

Allow the user to display all courses

Allow the user to add courses

Allow the user to delete courses

Save the data at the end of the program. Use at least two structures and one enum.

EX: Computer Science I, CSC110, Mon, Wed, 8:00, 9:00, Online, Zoom, Instructor

Answer 1

1.. Allow the user to add course

{

   Node head; // head of list

 

   //linked list node declaration

   class Node

{

   int data;

   Node next;

   Node(int d) {data = d; next = null; }

}

 

/* Insert a new node at the front of the list */

public void push(int new_data)

{

   //allocate and assign data to the node

   Node newNode = new Node(new_data);

 

   //new node becomes head of linked list

   newNode.next = head;

 

   //head points to new node

   head = newNode;

}

 

// Given a node,prev_node insert node after prev_node

public void insertAfter(Node prev_node, int new_data)

{

   //check if prev_node is null.

   if (prev_node == null)

   {

      System.out.println("The given node is required and cannot be null");

      return;

   }

 

//allocate node and assign data to it

Node newNode = new Node(new_data);

 

//next of new Node is next of prev_node

newNode.next = prev_node.next;

 

//prev_node->next is the new node.

prev_node.next = newNode;

}

    //inserts a new node at the end of the list

public void append(intnew_data)

    {

        //allocate the node and assign data

        Node newNode = new Node(new_data);

 

        //if linked list is empty, then new node will be the head

if (head == null)

        {

head = new Node(new_data);

return;

        }

 

        //set next of new node to null as this is the last node

newNode.next = null;

 

// if not the head node traverse the list and add it to the last

Node last = head;

while (last.next != null)

last = last.next;

 

//next of last becomes new node

last.next = newNode;

return;

}

 

//display contents of linked list

public void displayList()

{

   Node pnode = head;

   while (pnode != null)

{

   System.out.print(pnode.data+"-->");

   pnode = pnode.next;

}

if(pnode == null)

System.out.print("null");

 

}

 

}

 

//Main class to call linked list class functions and construct a linked list

class Main{

public static void main(String[] args)

   {

   /* create an empty list */

   LinkedList lList = new LinkedList();

 

   // Insert 40.

   lList.append(40);

 

   // Insert 20 at the beginning.

   lList.push(20);

 

   // Insert 10 at the beginning.

   lList.push(10);

 

   // Insert 50 at the end.

   lList.append(50);

 

   // Insert 30, after 20.

   lList.insertAfter(lList.head.next, 30);

 

   System.out.println("\nFinal linked list: ");

   lList. displayList ();

   }

}

2..Allow the user to delete courses:

#include <iostream>

using namespace std;

 

/* Link list node */

struct Node {

   int data;

   struct Node* next;

   };

 

//delete first node in the linked list

Node* deleteFirstNode(struct Node* head)

{

   if (head == NULL)

   return NULL;

 

   // Move the head pointer to the next node

   Node* tempNode = head;

   head = head->next;

   delete tempNode;

 

   return head;

}

//delete last node from linked list

Node* removeLastNode(struct Node* head)

{

   if (head == NULL)

   return NULL;

 

   if (head->next == NULL) {

      delete head;

      return NULL;

   }

 

// first find second last node

Node* second_last = head;

while (second_last->next->next != NULL)

second_last = second_last->next;

 

// Delete the last node

delete (second_last->next);

 

// set next of second_last to null

second_last->next = NULL;

 

return head;

}

 

// create linked list by adding nodes at head

void push(struct Node** head, int new_data)

{

   struct Node* newNode = new Node;

   newNode->data = new_data;

   newNode->next = (*head);

   (*head) = newNode;

}

 

// main function

int main()

{

   /* Start with the empty list */

   Node* head = NULL;

 

   // create linked list

   push(&head, 2);

   push(&head, 4);

   push(&head, 6);

   push(&head, 8);

   push(&head, 10);

 

         Node* temp;

 

   cout<<"Linked list created "<<endl; for (temp = head; temp != NULL; temp = temp->next)

   cout << temp->data << "-->";

   if(temp == NULL)

   cout<<"NULL"<<endl;

 

       //delete first node

   head = deleteFirstNode(head);

   cout<<"Linked list after deleting head node"<<endl; for (temp = head; temp != NULL; temp = temp->next)

   cout << temp->data << "-->";

   if(temp == NULL)

   cout<<"NULL"<<endl;

 

      //delete last node

   head = removeLastNode(head);

   cout<<"Linked list after deleting last node"<<endl; for (temp = head; temp != NULL; temp = temp->next)

   cout << temp->data << "-->";

   if(temp == NULL)

   cout<<"NULL";

 

   return 0;

}