C++ Linked List Project

#include <iostream>
#include<fstream>
#include <iomanip>
#include<cstring>
#include<cctype>
#include<cstdlib>
using namespace std;

struct Nodetype;
typedef Nodetype* Nodeptr;

struct Nodetype //struct to hold information about each dog
{
long id;
char name[20];
char breed[50];
int position; //Keeps track of the position of the dog in the line
Nodeptr Left, Right;
int numnodes;  //Field is used only in the header node to keep track of # nodes
};
ofstream outs;

int main()
{
char choice[3];     //to hold choice made by user
char ch1,ch2;       //to separate out the characters choices.
Nodeptr Head;


void menu();
Nodeptr InitializeHeader();
void Createlist(Nodeptr Head);
void PrintList(Nodeptr Head);
void PrintFirst(Nodeptr Head);
void PrintLast(Nodeptr Head);
void Deletenode(Nodeptr Head);
void Replacenode(Nodeptr Head);
void Reposition(Nodeptr Head);
void Printanode(Nodeptr Head);
Nodeptr Search(Nodeptr Head, long idnum);
Nodeptr Search2(Nodeptr Head, int pos);
bool Empty(Nodeptr Head);
void Announce_Winner(Nodeptr Head);

Head = InitializeHeader();


menu();
cout<<endl;
for(int i=0;i<3;i++)
   choice[i] = ' ';
cout<<"Enter your choice."<<endl;
cin.getline(choice,3);
ch1 = choice[0];
ch1 = toupper(ch1);
ch2 = choice[1];
ch2 = toupper(ch2);
while (ch1 != 'Q')
   {
     switch(ch1)
    {
     case 'C':Createlist(Head);
              break;
     case 'P':PrintList(Head);
              break;
     case 'F': PrintFirst(Head);
               break;
     case 'L':PrintLast(Head);
              break;
     case 'D':switch(ch2)
          {
           case 'R':Replacenode(Head);
                    break;
           case '\0': Deletenode(Head);
                      break;
          }
           break;
     case 'R': Reposition(Head);
               break;
     case 'S': Printanode(Head);
               break;
     default : cout<<"Invalid choice. Try again!"<<endl;
    }
     cout<<endl;
     menu();
     for(int i=0;i<3;i++)
    choice[i] = ' ';
     cout<<"Please enter your choice."<<endl;
     cin.getline(choice,3);
     ch1 = choice[0];
     ch1 = toupper(ch1);
     ch2 = choice[1];
     ch2 = toupper(ch2);
   }
  Announce_Winner(Head);
  system("PAUSE");
  return 0;
}

/**************************************************************************
The following function displays the menu of option to the screen.
****************************************************************************/

void menu()
{
  cout<<"C or c    --- Create list of dogs competing in Best of Show."<<endl;
  cout<<"P or p    --- Print the list of dogs by position in line."<<endl;
  cout<<"F or f    --- Print the id, name, and breed of first place dog."<<endl;
  cout<<"L or l    --- Print the id, name, and breed of last place dog."<<endl;
  cout<<"D or d    --- Deletes a dog to be identified by id number."<<endl;
  cout<<"DR or dr  --- Replace a dog whose id number you specify."<<endl;
  cout<<"R or r    --- Allows the judge to reposition a dog in the line."<<endl;
  cout<<"S or s    --- Show the position,id,name,breed of dog speicifed by id."<<endl;
  cout<<"Q or q    --- Quit the program and announce the winner."<<endl;
  cout<<endl;
  return;
}

/**************************************************************************
This function initializes the list to an empty list.
****************************************************************************/

Nodeptr InitializeHeader()
{
   Nodeptr q;
   q = new Nodetype;
   q->Right = q;
   q->Left = q;
   q->numnodes = 0;
   q->position = 0;
   return q;
}

/****************************************************************************
This function adds a new node to the end of the existing list.
******************************************************************************/

void Createlist(Nodeptr Head)
{
  Nodeptr p,q;
  int idnum;
  int count;
  bool Empty(Nodeptr List);
  Nodeptr Search(Nodeptr List, long num);
  cout<<"Enter id number of the dog(-1 to stop):";
  cin>>idnum;
  cin.ignore();
  count = 0;
  while(idnum != -1)
     {
    p = Search(Head, idnum);
    if (p != NULL)
       cout<<"This dog is already in line!"<<endl;
    else
       {
         count++;
         q = new Nodetype;
         q->id = idnum;
         cout<<"Enter the dog's name:";
         cin.getline(q->name,20);
         cout<<"Enter the dog's breed:";
         cin.getline(q->breed,50);
         q->position = count;
         p = Head->Left;
         q->Right = Head;
         q->Left = p;
         p->Right = q;
         Head->Left = q;
         Head->numnodes++;
       }
    cout<<endl;
    cout<<"Enter id number of the dog(-1 to stop):";
    cin>>idnum;
    cin.ignore();
     }
  return;
}

/********************************************************************
This function will display the contents of each node in the list
both at the screen and in the external text file.
**************************************************************************/

void PrintList(Nodeptr Head)
{
   Nodeptr p;
   bool Empty(Nodeptr List);
   ofstream outs;

   outs.open("dogs.txt", ios::app);

   p = Head;
  if (Empty(Head))
      cout<<"List is empty."<<endl;
   else
      {
       cout<<"List of all dogs:"<<endl<<endl;
       outs<<"List of all dogs:"<<endl<<endl;

       cout<<"Position"<<setw(15)<<"ID Number"<<setw(19)<<"Breed"<<setw(15)<<"Name"
           <<endl;

       outs<<"Position"<<setw(15)<<"ID Number"<<setw(19)<<"Breed"<<setw(15)<<"Name"
           <<endl;

       do
       {
         p = p->Right;
         cout<<right<<setw(4)<<p->position<<setw(15)<<p->id<<setw(26)
             <<p->breed<<"        "<<left<<setw(10)<<p->name<<endl;
         outs<<right<<setw(4)<<p->position<<setw(15)<<p->id<<setw(26)
             <<p->breed<<"        "<<left<<setw(10)<<p->name<<endl;
       }
       while (p->Right !=Head);
      }
      cout<<right;

      outs.close();

     return;
}


/******************************************************************
This function is to display the name, breed, and position of the
dog who is in first place.
*********************************************************************/

void PrintFirst(Nodeptr Head)
{
  bool Empty(Nodeptr List);
  ofstream outs;

  outs.open("dogs.txt", ios::app);

   if (Empty(Head))
      cout<<"List is empty."<<endl;
   else
  {
   cout<<endl;
   cout<<"The dog first in line is:\n";
   cout<<"#"<<Head->Right->id<<": "<<Head->Right->name<<"  "<<Head->Right->breed<<endl;
   outs<<endl;
   outs<<"The dog first in line is:\n";
   outs<<"#"<<Head->Right->id<<": "<<Head->Right->name<<"  "<<Head->Right->breed<<endl;
  }
  cout<<endl<<endl;
  outs<<endl<<endl;

  outs.close();

  return;
}


/**********************************************************************
This function is to display the name, breed, and position of the
dog who is in last place.
*********************************************************************/

void PrintLast(Nodeptr Head)
{
  bool Empty(Nodeptr List);
  ofstream outs;

  outs.open("dogs.txt", ios::app);

  if (Empty(Head))
      cout<<"List is empty."<<endl;
   else
  {
   cout<<endl;
   cout<<"The dog last in line is:\n";
   cout<<"#"<<Head->Left->id<<": "<<Head->Left->name<<"  "<<Head->Left->breed<<endl;
   outs<<endl;
   outs<<"The dog last in line is:\n";
   outs<<"#"<<Head->Left->id<<": "<<Head->Left->name<<"  "<<Head->Left->breed<<endl;
  }
  cout<<endl;
  outs<<endl;

  outs.close();

  return;
}

/**********************************************************************
This function deletes a node from the list based upon the id number
of the dog that is specified.
***********************************************************************/

void Deletenode(Nodeptr Head)
{
 long idnum;
 int count;
 Nodeptr p;
 Nodeptr Search(Nodeptr List, long idnum);
 bool Empty(Nodeptr List);
 outs.open("dogs.txt", ios::app);

 if (Empty(Head))
    cout<<"Empty List!"<<endl;
 else
    {
      cout<<"Enter id number of the dog you wish to delete."<<endl;
      cin>>idnum;
      cin.ignore();
      p = Search(Head, idnum);
      if (p==NULL)
     cout<<"The dog is not in the line!"<<endl;
      else
     {
       p->Left->Right = p->Right;
       p->Right->Left = p->Left;
       delete p;
       Head->numnodes--;
       cout<<"Dog "<<idnum<<" removed from the line!"<<endl<<endl;
       outs<<"Dog "<<idnum<<" removed from the line!"<<endl<<endl;
       p = Head->Right;
       count = 0;
       while(p !=Head)
       {
           count++;
           p->position = count;
           p = p->Right;
       }
     }
    }
    outs.close();
 return;
}


/***************************************************************************
This function replaces a node(dog) in the list with another existing node (dog).
***********************************************************************/

void Replacenode(Nodeptr Head)
{
   long idnum;
   Nodeptr p, q, r;
   bool Empty(Nodeptr List);
   Nodeptr Search(Nodeptr List, long idnum);
   int temp = 0;
   ofstream outs;

   outs.open("dogs.txt", ios::app);

   if (Empty(Head))
      cout<<"List is empty."<<endl;
   else
   {
      cout<<"Enter id number of the dog you wish to move."<<endl;
      cin>>idnum;
      cin.ignore();
      p = Search(Head, idnum);
      if (p==NULL)
      cout<<"The dog is not in the line!"<<endl;
      else
       {
          q = p;
          cout<<"Enter the id number of the dog you wish to replace."<<endl;
          cin>>idnum;
          cin.ignore();
          p = Search(Head, idnum);
          if (p==NULL)
          cout<<"The dog is not in the line!"<<endl;
          else
            {
             cout<<"Replacing dog..."<<endl;
             outs<<"Replacing dog..."<<endl;
            q->Left->Right = q->Left->Right->Right;
            q->Right->Left = q->Right->Left->Left;
            q->Right = NULL;
            q->Left = NULL;
            q->Left = p->Left;
            q->Right = p->Right;
            p->Left->Right = q;
            p->Right->Left = q;
            p->Left = NULL;
            p->Right = NULL;
            delete p;

            r = Head->Right;
            temp = 1;

             do
            {
             r->position = temp;
             r = r->Right;
             temp++;
            }while(r != Head);

            cout<<"Dog successfully replaced."<<endl<<endl;
            outs<<"Dog successfully replaced."<<endl<<endl;
            }
       }
   }

   outs.close();
   return;
}


/*********************************************************************
This function is to reposition a dog in the line.
*****************************************************************************/
void Reposition(Nodeptr Head)
{

   bool Empty(Nodeptr List);
   Nodeptr p, q, r;
   Nodeptr Search2(Nodeptr List, int pos);
   int pos, temp;
   temp = 0;
   outs.open("dogs.txt", ios::app);

   if (Empty(Head))
      cout<<"List is empty."<<endl;
   else
   {
    cout<<"Enter position of the dog you wish to move."<<endl;
      cin>>pos;
      cin.ignore();
      p = Search2(Head, pos);
      if (p==NULL)
      cout<<"That position does not exist!"<<endl;
      else
       {
       q = p;
       cout<<"Which position do you want to move it to?"<<endl;
       cin>>pos;
       cin.ignore();
       p = Search2(Head, pos);
       if (p==NULL)
       cout<<"That position does not exist!"<<endl;
        else
         {
          if((p->position) < (q->position))
          { //Move node from right to left
            cout<<"Moving dog..."<<endl;
            outs<<"Moving dog..."<<endl;
            q->Left->Right = q->Left->Right->Right;
            q->Right->Left = q->Right->Left->Left;
            q->Right = NULL;
            q->Left = NULL;
            q->Left = p->Left;
            p->Left->Right = q;
            p->Left = q;
            q->Right = p;

            r = Head->Right;
            temp = 1;

            do
            {
                r->position = temp;
                r = r->Right;
                temp++;
            }while(r != Head);
            cout<<"Dog successfully moved."<<endl<<endl;
            outs<<"Dog successfully moved."<<endl<<endl;
            }
          else
             {//Move node from left to right
             cout<<"Moving dog..."<<endl;
             outs<<"Moving dog..."<<endl;
             q->Left->Right = q->Left->Right->Right;
             q->Right->Left = q->Right->Left->Left;
             q->Right = NULL;
             q->Left = NULL;
             q->Right = p->Right;
             p->Right->Left = q;
             p->Right = q;
             q->Left = p;

            r = Head->Right;
            temp = 1;

            do
            {
                r->position = temp;
                r = r->Right;
                temp++;
            }while(r != Head);
            cout<<"Dog successfully moved."<<endl<<endl;
            outs<<"Dog successfully moved."<<endl<<endl;
            }

         }
       }
    }

   outs.close();
   return;
}

/***********************************************************************
This function is to display the information of a dog in line, identified
by id number.
*************************************************************************/

void Printanode(Nodeptr Head)
{
  int idnum;
  Nodeptr p;
  bool Empty(Nodeptr List);
  Nodeptr Search(Nodeptr List, long num);
  outs.open("dogs.txt", ios::app);

  if (Empty(Head))
      cout<<"List is empty."<<endl;
   else
  {
       cout<<"Enter the ID number of the dog:"<<endl;
       cin>>idnum;
       cin.ignore();
       p = Search(Head, idnum);
       if (p == NULL)
      cout<<"This dog is not in the line."<<endl;
       else
      {
         cout<<"Locating dog at position: "<<p->position<<endl;
         cout<<"Position #"<<p->position<<": "<<" Id number "<<p->id
             <<" : "<<p->name<<endl<<endl;

         outs<<"Locating dog at position: "<<p->position<<endl;
         outs<<"Position #"<<p->position<<": "<<" Id number "<<p->id
             <<" : "<<p->name<<endl<<endl;

      }
     }

     outs.close();
  return;
}

/***************************************************************************
This function searches for a dog in the list based upon the dog's id number.
****************************************************************************/

Nodeptr Search(Nodeptr Head, long idnum)
{
  int found = 0;
  Nodeptr p;
  bool Empty(Nodeptr List);

  if (Empty(Head))
     return NULL;
  else
     {
       p = Head->Right;
       do
     {
       if (idnum == p->id)
          found = 1;
       else
          p = p->Right;

      }while (!found &&(p != Head));
       if (p != Head)
      return p;
       else
      return NULL;
     }
}

/****************************************************************************
This function searches for a dog in the list based upon the dog's position
in the list.
****************************************************************************/

Nodeptr Search2(Nodeptr Head, int pos)
{
  int found = 0;
  Nodeptr p;
  bool Empty(Nodeptr List);

  if (Empty(Head))
     return NULL;
  else
     {
       p = Head->Right;
       do
     {
       if (pos == p->position)
          found = 1;
       else
          p = p->Right;

      }while (!found &&(p != Head));
       if (p != Head)
      return p;
       else
      return NULL;
     }
}

/*********************************************************************
This function checks for an empty list.
**********************************************************************/

bool Empty(Nodeptr Head)
{
   if ((Head->Right == Head) && (Head->Left == Head))
      return true;
   else
      return false;
}

/**************************************************************************
This function announces the winner of "Best in Show" both at the screen
and at the external text file.
****************************************************************************/

void Announce_Winner(Nodeptr Head)
{
  bool Empty(Nodeptr List);
  ofstream outs;

  outs.open("dogs.txt", ios::app);

  if (Empty(Head))
      cout<<"List is empty."<<endl;
   else
   {
       cout<<"The winner of Best in Show is: "<<Head->Right->name<<"!!"<<endl;
       outs<<"The winner of Best in Show is: "<<Head->Right->name<<"!!"<<endl;
   }

  outs.close();


  return;
}