Question

Write a program that will read the information from a file into a list and then display the list to the screen.
Remove the fifth item in the list and display the list again. Ask the program user for an entry into
the list and add it to the list. Display the list one last time.

disneyin.txt file

daisy   123
donald   345
goofy   654
mickey   593
minnie   489
daffy   432
pluto   765
huey   321
dewey   987
lewey   554
porky   333
buggs   778

list.h

#ifndef LIST_H_
#define LIST_H_

template <typename BaseData>
class List
{
//template <typename ifstream, typename empData>
//friend ifstream &operator>>(ifstream &input, empData temp);
//template <typename ostream, typename inStruct>
//friend ostream &operator<<(ifstream& output, empData inStruct);

protected:
struct ListNode
{
public:
BaseData listData;
ListNode* link;
};

public:

List();
List(List& init);
~List();
void first();
void last();
void makeCurrent(int position);
void prev();
void next();
int current();
int count();
void insertBefore(const BaseData& item);
void insertAfter(const BaseData& item);
void remove();
void replace(BaseData& item);
BaseData* examine();
List<BaseData>& operator = (List<BaseData>& source);
void destroy();

protected:

ListNode* head, * currentNode, * previous;
int numNodes;
int currentPos;

};

#include "list.t"
#endif

list.t

#ifndef LIST_T_
#define LIST_T_

  
template <class BaseData>
List <BaseData>::List()
{
previous = 0;
currentNode = 0;
head = 0;
numNodes = 0;
currentPos = 0;
}

template <class BaseData>
List <BaseData>::List(List<BaseData> &init)
{
if (this == &init) return;
ListNode *newList, *current, *newNode;
current = init.head;
newList = 0;
head = 0;
while (current)
{
newNode = new ListNode;
newNode->listData = current->listData;
newNode->link = 0;

if (newList)
{
newList->link = newNode;
newList = newList->link;
}

else newList = newNode;

if (current == init.head)
head = newNode;
current = current->link;
}

numNodes = init.numNodes;
currentPos = 0;
previous = 0;
currentNode = 0;
}

template <class BaseData>
void List <BaseData>::insertBefore(const BaseData &item)
{
ListNode *p;
p = new ListNode;
p->listData = item;
if (numNodes)
{
if (head == currentNode) head = p;
p->link = currentNode;
if (previous) previous ->link = p;
++numNodes;
currentNode = p;
}
else
{
head = p;
p->link = 0;
previous = 0;
++numNodes;
currentNode = p;
}
}

template <class BaseData>
BaseData * List<BaseData>::examine()
{
BaseData *temp;
if (currentNode)
{
temp = new BaseData;
*temp = currentNode->listData;
return (temp);
}
else
return 0;
}

template <class BaseData>
List <BaseData>::~List()
{
destroy();
}

template <class BaseData>
void List<BaseData>::destroy()
{
ListNode *temp;
currentNode = head;
while (currentNode)
{
temp = currentNode;
currentNode = currentNode->link;
delete temp;

}

previous = 0;
currentNode = 0;
head = 0;
numNodes = 0;
currentPos = 0;
}

template <class BaseData>
void List <BaseData>::first()
{
if (numNodes)
{
previous = 0;
currentNode = head;
currentPos = 1;
}
else
currentPos = 0;
}

template <class BaseData>
void List <BaseData>::last()
{
while (currentNode->link)
{
previous = currentNode;
currentNode = currentNode->link;
}
currentPos = numNodes;
}

template <class BaseData>
void List<BaseData>::makeCurrent (int position)
{
if (( position < 1) || (position > numNodes))
cout << "invalid position: "<< endl;
else
{
first();
for (int i = 1; i < position; i++)
{
previous = currentNode;
currentNode = currentNode->link;
}
currentPos = position;
}
}

template <class BaseData>
void List<BaseData>::prev()
{
int tempCurrPos = currentPos;
if (currentPos > 1)
{
ListNode *temp = previous;
first();
if (currentNode == temp)
{
previous = 0;
currentNode = temp;
}
else
{
while (currentNode->link != temp)
currentNode = currentNode->link;
previous = currentNode;
currentNode = temp;
}
currentPos = tempCurrPos -1;
}
else
{
cout << "walking over front of list";
currentPos = 0;
}

}

template <class BaseData>
void List<BaseData>::next()
{
if (currentNode->link)
{
previous = currentNode;
currentNode = currentNode->link;
currentPos++;
}
else
{
cout << "walking over end of list";
currentPos = 0;
}
}

template <class BaseData>
int List<BaseData>::current()
{
return (currentPos);
}

template <class BaseData>
int List<BaseData>::count()
{
return (numNodes);
}

template <class BaseData>
void List<BaseData>::insertAfter(const BaseData &item)
{
ListNode *p;
p = new ListNode;
p->listData = item;
if (numNodes)
{
p->link = currentNode->link;
currentNode->link = p;
++numNodes;
previous = currentNode;
currentNode = p;
currentPos++;
}
else
{
head = p;
p->link = 0;
previous = 0;
++numNodes;
currentNode = p;
currentPos++;
}
}

template <class BaseData>
void List<BaseData>::remove()
{
ListNode *p, *temp;
p = currentNode;
if (numNodes)   //there are nodes
{if (previous)   //this is not the first node in the list
{   //any other node in list but first
previous->link = currentNode->link;
if (currentNode->link != 0)
currentNode = currentNode->link;
else   //deleting last node in list
{
currentPos--;
currentNode = previous;
temp = head;
if (temp == currentNode)
previous = 0;
else
{
while (temp->link != currentNode && temp)
temp = temp->link;
previous = temp;
}
}
delete p;
--numNodes;
}
else
{   //delete first node in list
head = head->link;
delete p;
currentNode = head;
--numNodes;

//if first and last node in list
if (!numNodes) currentPos = 0;
}
}
else cout << "empty list" << endl;
}

template <class BaseData>
void List<BaseData>::replace(BaseData &item)
{
if (currentNode)
currentNode->listData = item;
}

template <class BaseData>
List<BaseData>& List<BaseData>:: operator = (List<BaseData> &init)
{
if (this == &init) return *this;

ListNode *temp, *newList, *current, *newNode;
currentNode = head;
while (currentNode) //delete existing left side list
{
temp = currentNode;
currentNode = currentNode->link;
delete temp;
}

current = init.head;
newList = 0;
while (current) //copy list
{ newNode = new ListNode;
newNode->listData = current->listData;
newNode->link = 0;
if (newList)
{
newList->link = newNode;
newList = newList->link;
}
else newList = newNode;
if (current == init.head)
head = newNode;
current = current->link;
}

numNodes = init.numNodes;
currentPos = 0;
previous = 0;
currentNode = 0;
return *this;
}
//----------------i added this-----------------
//extraction/insertion operators have to be a friend function
/*
template <typename ifstream, typename empData>
ifstream &operator>>(ifstream &input, empData temp)
{
   //input >> "take in the employee name"
   input >> temp.empName;
   //input >> "take in the employee ID num"
   input >> temp.empID;
  
return temp;
}

template <typename ostream, typename empData>
ifstream &operator<<(ostream &output, empData inStruct)
{
  
   //output << inStruct.empName;
   //output << inStruct.empID;
  
return inStruct.empName << inStruct.empId;
}
*/

#endif

Answer 1

Rawcode:

1.list.cpp

#include "list.h"

2.lab4_client_driver.cpp

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

#include "list.h"

struct Disney
{
   string name;
   int id;
};

int main(){
   ifstream inFile;

   string fileName;

   cout << "Please enter your file name:";
   cin >> fileName;

   inFile.open(fileName.c_str());

   if (!inFile){
       cout << "cannot open the input file" << endl;
       return 1;
   }

   Disney data;
   List<string> name;
   List<int> id;

   string *nameP;
   int *idP;

   inFile >> data.name >> data.id;
   while (inFile){

       name.insertAfter(data.name);
       id.insertAfter(data.id);

       nameP = name.examine();
       idP = id.examine();
       cout << *nameP << " " << *idP << endl;

       inFile >> data.name >> data.id;
   }
   inFile.close();

   cout << endl;

   cout << "After deleting the fifth element:" << endl;

   inFile.open(fileName.c_str());

   if (inFile){
       name.makeCurrent(5);
       nameP = name.examine();
       name.remove();
       id.makeCurrent(5);
       idP = id.examine();
       id.remove();

   }

   name.first();
   id.first();
   inFile >> data.name >> data.id;
   while (inFile){
       nameP = name.examine();
       idP = id.examine();
      
       if (name.current() != name.count())
       {
           cout << *nameP << " " << *idP << endl;
           name.next();
           id.next();
       }

       else{
           cout << *nameP << " " << *idP << endl;
           break;
       }

       inFile >> data.name >> data.id;
   }
   inFile.close();

   cout << endl;

   cout << "Please enter the name and id: ";
   cin >> data.name >> data.id;

   inFile.open(fileName.c_str());

   if (inFile){
       name.last();
       name.insertAfter(data.name);
       id.last();
       id.insertAfter(data.id);
   }

   name.first();
   id.first();
   inFile >> data.name >> data.id;
   while (inFile){
       nameP = name.examine();
       idP = id.examine();
       cout << *nameP << " " << *idP << endl;
       if (name.current() != name.count()){
           name.next();
           id.next();
       }
       inFile >> data.name >> data.id;
   }
   inFile.close();

   return 0;
}

code in my editor:

output:

Please enter your file name : disneyin.txt
daisy 123
donald 345
goofy 654
mickey 593
minnie 489
daffy 432
pluto 765
huey 321
dewey 987
lewey 554
porky 333
buggs 778
After deleting the fifth element :
daisy 123
donald 345
goofy 654
mickey 593
daffy 432
pluto 765
huey 321
dewey 987
lewey 554
porky 333
buggs 778
Please enter the name and id : chip 178
daisy 123
donald 345
goofy 654
mickey 593
daffy 432
pluto 765
huey 321
dewey 987
lewey 554
porky 333
buggs 778
chip 178
Press any key to continue . . .

Please do up vote.

Thanks.