The document outlines the implementation of an `unsortedlist` class in C++ to manage a list of numbers read from a file (data.txt). It describes operations such as inserting and deleting items, retrieving the length of the list, and printing the entire list, as well as the greatest and least elements. Additionally, it provides code examples for a main driver program and the class implementation, including methods for managing and accessing list items.

1. Using the C++ programming language
1. Implement the UnsortedList class to store a list of numbers that are input into the list from
data.txt.
- create a main.cpp file that gets the numbers from the file
- insert the number 7 into the list
- insert another number 300 into the list
- delete the number 6 from the list
- print out the following:
--the entire list
- the greatest
- the least
2. Attach the main.cpp, UnsortedList.cpp, the ItemType.h, and the output file two called
outfile2.txt
Use the files below:
// listDriver.cpp
// Test driver
#include
#include
#include
#include
#include
#include "unsorted.h"
using namespace std;
void PrintList(ofstream& outFile, UnsortedType& list);
int main()
{
ifstream inFile; // file containing operations
ofstream outFile; // file containing output
string inFileName; // input file external name
string outFileName; // output file external name
string outputLabel;
string command; // operation to be executed
int number;
ItemType item;

2. UnsortedType list;
bool found;
int numCommands;
// Prompt for file names, read file names, and prepare files
cout << "Enter name of input command file; press return." << endl;
cin >> inFileName;
inFile.open(inFileName.c_str());
cout << "Enter name of output file; press return." << endl;
cin >> outFileName;
outFile.open(outFileName.c_str());
cout << "Enter name of test run; press return." << endl;
cin >> outputLabel;
outFile << outputLabel << endl;
if (!inFile)
{
cout << "file not found" << endl;
exit(2)
}
inFile >> command;
numCommands = 0;
while (command != "Quit")
{
if (command == "PutItem")
{
inFile >> number;
item.Initialize(number);
list.PutItem(item);
item.Print(outFile);
outFile << " is in list" << endl;
}
else if (command == "DeleteItem")
{
inFile >> number;
item.Initialize(number);
list.DeleteItem(item);

3. item.Print(outFile);
outFile << " is deleted" << endl;
}
else if (command == "GetItem")
{
inFile >> number;
item.Initialize(number);
item = list.GetItem(item, found);
item.Print(outFile);
if (found)
outFile << " found in list." << endl;
else outFile << " not in list." << endl;
}
else if (command == "GetLength")
outFile << "Length is " << list.GetLength() << endl;
else if (command == "IsFull")
if (list.IsFull())
outFile << "List is full." << endl;
else outFile << "List is not full." << endl;
else if (command == "MakeEmpty")
list.MakeEmpty();
else if (command == "PrintList")
PrintList(outFile, list);
else
cout << command << " is not a valid command." << endl;
numCommands++;
cout << " Command number " << numCommands << " completed."
<< endl;
inFile >> command;
};
cout << "Testing completed." << endl;
inFile.close();
outFile.close();
return 0;
}

4. void PrintList(ofstream& dataFile, UnsortedType& list)
// Pre: list has been initialized.
// dataFile is open for writing.
// Post: Each component in list has been written to dataFile.
// dataFile is still open.
{
int length;
ItemType item;
list.ResetList();
length = list.GetLength();
for (int counter = 1; counter <= length; counter++)
{
item = list.GetNextItem();
item.Print(dataFile);
}
dataFile << endl;
}
//unsorted.cpp
// This file contains the linked implementation of class
// UnsortedType.
#include "unsorted.h"
struct NodeType
{
ItemType info;
NodeType* next;
};
UnsortedType::UnsortedType() // Class constructor
{
length = 0;
listData = NULL;
}
bool UnsortedType::IsFull() const
// Returns true if there is no room for another ItemType
// on the free store; false otherwise.
{

5. NodeType* location;
try
{
location = new NodeType;
delete location;
return false;
}
catch(std::bad_alloc exception)
{
return true;
}
}
int UnsortedType::GetLength() const
// Post: Number of items in the list is returned.
{
return length;
}
void UnsortedType::MakeEmpty()
// Post: List is empty; all items have been deallocated.
{
NodeType* tempPtr;
while (listData != NULL)
{
tempPtr = listData;
listData = listData->next;
delete tempPtr;
}
length = 0;
}
void UnsortedType::PutItem(ItemType item)
// item is in the list; length has been incremented.
{
NodeType* location; // Declare a pointer to a node
location = new NodeType; // Get a new node
location->info = item; // Store the item in the node
location->next = listData; // Store address of first node

6. // in next field of new node
listData = location; // Store address of new node into
// external pointer
length++; // Increment length of the list
}
ItemType UnsortedType::GetItem(ItemType& item, bool& found)
// Pre: Key member(s) of item is initialized.
// Post: If found, item's key matches an element's key in the
// list and a copy of that element has been stored in item;
// otherwise, item is unchanged.
{
bool moreToSearch;
NodeType* location;
location = listData;
found = false;
moreToSearch = (location != NULL);
while (moreToSearch && !found)
{
switch (item.ComparedTo(location->info))
{
case LESS :
case GREATER : location = location->next;
moreToSearch = (location != NULL);
break;
case EQUAL : found = true;
item = location->info;
break;
}
}
return item;
}
void UnsortedType::DeleteItem(ItemType item)
// Pre: item's key has been initialized.
// An element in the list has a key that matches item's.
// Post: No element in the list has a key that matches item's.
{

7. NodeType* location = listData;
NodeType* tempLocation;
// Locate node to be deleted.
if (item.ComparedTo(listData->info) == EQUAL)
{
tempLocation = location;
listData = listData->next; // Delete first node.
}
else
{
while (item.ComparedTo((location->next)->info) != EQUAL)
location = location->next;
// Delete node at location->next
tempLocation = location->next;
location->next = (location->next)->next;
}
delete tempLocation;
length--;
}
void UnsortedType::ResetList()
// Post: Current position has been initialized.
{
currentPos = NULL;
}
ItemType UnsortedType::GetNextItem()
// Post: A copy of the next item in the list is returned.
// When the end of the list is reached, currentPos
// is reset to begin again.
{
ItemType item;
if (currentPos == NULL)
currentPos = listData;
else
currentPos = currentPos->next;
item = currentPos->info;

8. return item;
}
UnsortedType::~UnsortedType()
// Post: List is empty; all items have been deallocated.
{
NodeType* tempPtr;
while (listData != NULL)
{
tempPtr = listData;
listData = listData->next;
delete tempPtr;
}
}
//unsorted.h
#include "ItemType.h"
// File ItemType.h must be provided by the user of this class.
// ItemType.h must contain the following definitions:
// MAX_ITEMS: the maximum number of items on the list
// ItemType: the definition of the objects on the list
// RelationType: {LESS, GREATER, EQUAL}
// Member function ComparedTo(ItemType item) which returns
// LESS, if self "comes before" item
// GREATER, if self "comes after" item
// EQUAL, if self and item are the same
struct NodeType;
class UnsortedType
{
public:
UnsortedType();
// Constructor
~UnsortedType();
// Destructor
void MakeEmpty();
// Function: Returns the list to the empty state.
// Post: List is empty.
bool IsFull() const;

9. // Function: Determines whether list is full.
// Pre: List has been initialized.
// Post: Function value = (list is full)
int GetLength() const;
// Function: Determines the number of elements in list.
// Pre: List has been initialized.
// Post: Function value = number of elements in list
ItemType GetItem(ItemType& item, bool& found);
// Function: Retrieves list element whose key matches item's key (if
// present).
// Pre: List has been initialized.
// Key member of item is initialized.
// Post: If there is an element someItem whose key matches
// item's key, then found = true and someItem is returned;
// otherwise found = false and item is returned.
// List is unchanged.
void PutItem(ItemType item);
// Function: Adds item to list.
// Pre: List has been initialized.
// List is not full.
// item is not in list.
// Post: item is in list.
void DeleteItem(ItemType item);
// Function: Deletes the element whose key matches item's key.
// Pre: List has been initialized.
// Key member of item is initialized.
// One and only one element in list has a key matching item's key.
// Post: No element in list has a key matching item's key.
void ResetList();
// Function: Initializes current position for an iteration through the list.
// Pre: List has been initialized.
// Post: Current position is prior to list.
ItemType GetNextItem();
// Function: Gets the next element in list.
// Pre: List has been initialized and has not been changed since last call.
// Current position is defined.

10. // Element at current position is not last in list.
//
// Post: Current position is updated to next position.
// item is a copy of element at current position.
private:
NodeType* listData;
int length;
NodeType* currentPos;
};
//
ItemType.h
// The following declarations and definitions go into file
// ItemType.h.
#include
const int MAX_ITEMS = 5;
enum RelationType {LESS, GREATER, EQUAL};
class ItemType
{
public:
ItemType();
RelationType ComparedTo(ItemType) const;
void Print(std::ostream&) const;
void Initialize(int number);
private:
int value;
};
//data.txt
10 8 250 800 -1 6
Solution
#include
#include
#include
#include
#include

11. #include "unsorted.h"
using namespace std;
void PrintList(ofstream& outFile, UnsortedType& list);
int main()
{
ifstream inFile; // file containing operations
ofstream outFile; // file containing output
string inFileName; // input file external name
string outFileName; // output file external name
string outputLabel;
string command; // operation to be executed
int number;
ItemType item;
UnsortedType list;
bool found;
int numCommands;
// Prompt for file names, read file names, and prepare files
cout << "Enter name of input command file; press return." << endl;
cin >> inFileName;
inFile.open(inFileName.c_str());
cout << "Enter name of output file; press return." << endl;
cin >> outFileName;
outFile.open(outFileName.c_str());
cout << "Enter name of test run; press return." << endl;
cin >> outputLabel;
outFile << outputLabel << endl;
if (!inFile)
{
cout << "file not found" << endl;
exit(2)
}
inFile >> command;
numCommands = 0;
while (command != "Quit")

12. {
if (command == "PutItem")
{
inFile >> number;
item.Initialize(number);
list.PutItem(item);
item.Print(outFile);
outFile << " is in list" << endl;
}
else if (command == "DeleteItem")
{
inFile >> number;
item.Initialize(number);
list.DeleteItem(item);
item.Print(outFile);
outFile << " is deleted" << endl;
}
else if (command == "GetItem")
{
inFile >> number;
item.Initialize(number);
item = list.GetItem(item, found);
item.Print(outFile);
if (found)
outFile << " found in list." << endl;
else outFile << " not in list." << endl;
}
else if (command == "GetLength")
outFile << "Length is " << list.GetLength() << endl;
else if (command == "IsFull")
if (list.IsFull())
outFile << "List is full." << endl;
else outFile << "List is not full." << endl;
else if (command == "MakeEmpty")
list.MakeEmpty();
else if (command == "PrintList")

13. PrintList(outFile, list);
else
cout << command << " is not a valid command." << endl;
numCommands++;
cout << " Command number " << numCommands << " completed."
<< endl;
inFile >> command;
};
cout << "Testing completed." << endl;
inFile.close();
outFile.close();
return 0;
}