Question

C++ program:

Define a structure to hold the contact's information including: name, phone number, and a pointer to the next node on the list. Each node on the list will be a contact instead of a number (like the example in the book).

struct ContactNode
{
string name;
string phoneNumber;
ContactNode *next;
}

2. Define a class containing the structure, private member variable head (that will point to the beginning of the list) and the following member functions:
   • A constructor that will initialize the head
   • A destructor that will destroy the list. This method needs to delete one node at a time.
   • A method to add contacts to the list. This method must insert a node at the right place in order to keep the list sorted.
   • A method to traverse the list to print all contacts

You can find an implementation for those operations in the book and slides.

Your main program should instantiate an object of the Names List and ask the user to enter a list of names (first and last), which you will insert in alphabetical order by calling the appropriate method. When the user is done entering the names, call the displayList method to display the names, which should be in alphabetical order.

Turn in the list implementation in a header file and main.cpp

Answer 1

main.cpp file:

#include <iostream>
#include <string>
#include "contact.h"
using namespace std;

int main() {
    // welcome message
   cout << "Welcome to Contact List Program!" << endl;
   // create Contact list object
   ContactList list;
   // while loop to enter list of contacts
   while (true) {
       //ask user to enter new contact or exit
       cout << "Enter new Contact in list(enter -1 to exit)" << endl;
       cout << "Enter Name (first and last): ";
       string name; //string to hold name of contact
       getline(cin, name); //get user input
       // check if user entered "-1"
       if (name.compare("-1") == 0) {
           break; // break the loop as user done entering contacts
       }
       else {
           // ask user to enter phone number
           cout << "Enter Phone Number: ";
           string number; //string to hold phone number
           getline(cin, number); //get user input
           // insert contact into the list
           list.add(name, number);
       }
   }//end of loop
   // print list befor program exit
   list.print();
}

contact.h (header) file with implimentation:

#pragma once
#include <iostream>
using namespace std;

struct ContactNode {
   string name;
   string phoneNumber;
   ContactNode* next;
};

class ContactList {
private:
   ContactNode* head;
public:
   ContactList(); //constructor
   ~ContactList(); //destructor
   void add(string name, string phoneNumber); //function to add contact to list in sorted order
   void print(); //print all contacts in list
};

ContactList::ContactList() {
   // initialize private member
   head = nullptr;
}

ContactList::~ContactList() {
   // destructor to delete list
   // loop through list and delete one node at a time
   while (head != nullptr) {
       //create temparary node to delete the node and free memory
       ContactNode* temp = head; //assign temp to head(current node)
       head = head->next; //move head to next node
       delete temp; //delete current node
   }
}
void ContactList::add(string _name, string _phoneNumber) {
   // function to add contact in the list in alphabetical order by name
   // create a new contactnode
   ContactNode* node = new ContactNode();
   node->name = _name; //initialize name
   node->phoneNumber = _phoneNumber; //initialize phone number
   node->next = nullptr; //set next of node to nullptr
   //check if head is nullptr
   if (head == nullptr) {
       // set new node to head
       head = node;
   }
   else {
       // loop through the list and insert node at proper location in the list
       // create iterator to loop the list
       ContactNode* i = head; //set iterator to start of list
       bool inserted = false; //create flag to check that node is not inserted
       while (i->next != nullptr) {
           // loop till end of list
           // check for current node's name if greater then new node's name
           if (i->name.compare(node->name) > 0) { //this can only happen when current node is first node(head)
               // insert new node at start of the list
               node->next = head;
               head = node; //reset head to start of the list
               inserted = true; //set flag to true
               break; //break the loop as node insertion is done
           }
           else {
               // check for next node's name
               if (i->next->name.compare(node->name) > 0) {
                   // if next node's name is greater then new node's name then
                   // insert new node between current node and next node
                   node->next = i->next; //set new node's next to next node
                   i->next = node; //set current node's next to new node
                   inserted = true; //set flag to true
                   break; //break the while loop as node is inserted in thee list
               }
               else {
                   // when next node's name is less then new node's name, move forword in the list
                   i = i->next; //set iterator to next node
               }
           }
       }
       // if node is not inseted till end of the list
       if (!inserted) {
           // check for current node's name if greater then new node's name
           if (i->name.compare(node->name) > 0) { //this can only happen when current node is first node(head)
               // insert new node at start of the list
               node->next = head;
               head = node; //reset head to start of the list
           }
           else {
               // insert the node at end of the list
               i->next = node;
           }
       }
   }
}

void ContactList::print() {
   // function to print all contact in alphabetical order from the list
   // print line indicating print function
   cout << "The Contact List is :" << endl;
   // create iterator to loop the list
   ContactNode* itr = head; //set iterator to start of list
   // loop till itr is nullptr
   while (itr != nullptr) {
       cout << "Name: " << itr->name << endl; //print name
       cout << "Phone Number: " << itr->phoneNumber << endl; //print phone number
       cout << endl; //create empty line to seprate contacts from each other
       itr = itr->next; //move iterator to next node
   }
}