Explaining the Data Structure

[aquilina]

Hi i'm trying to read out the some code that i search in google. And i try to differentiate the code whether its using what kind of data structure.. Its using binary tree, queue, tree or vector or others?

#include<iostream.h>
#include<time.h>
#include<math.h>
#include<iomanip>



class studentrecord
{
public:
    studentrecord();
    char fname[10];
    char lname[10];
    int ID;
    char programme[10];
    int year_of_study;
    studentrecord *nxt;
    void register_student();
    void display_all();
    void displayStudentInformation();
    void Swap();
    void SearchStudent(); 
    void DeleteStudent();
    void ConditionalDisplay();
};
studentrecord::studentrecord()
{
}
studentrecord *start_ptr=NULL;
int khetho=0;

void studentrecord::register_student()
{
    studentrecord *temp,*temp2;
    temp=new studentrecord;
    cout<<"enter the student fist name:"<<endl;
    cin>>temp->fname;
    cout<<"enter student last name:"<<endl;
    cin>>temp->lname;
    cout<<"enter student id:"<<endl;
    cin>>temp->ID;
    cout<<"Enter the Programme of the student:"<<endl;
    cin>>temp->programme;
    cout<<"Enter student's year:"<<endl;
    cin>>temp->year_of_study;
    temp->nxt=NULL;

    
    if(start_ptr==NULL)
    {
        start_ptr=temp;
    }
    else
    {
        temp2=start_ptr;

  while(temp2->nxt!=NULL)
  {
      temp2=temp2->nxt;
  }
  temp2->nxt=temp;
    }
}
void studentrecord::display_all()
{
    studentrecord *temp;
   temp=start_ptr;
if(start_ptr==NULL)
{
    cout<<"the record is empty"<<endl;
}
else
{

while(temp!=NULL)
{
    cout<<"last name is:"<<temp->lname<<endl;
    cout<<"ID:"<<temp->ID<<endl;
    cout<<"first name is:"<<temp->fname<<endl;
    cout<<"the programme is:"<<temp->programme<<endl;
    cout<<endl;
    cout<<endl;

    temp=temp->nxt;
}
}
}

void studentrecord::Swap()
{   studentrecord *temp,*temp2,*temp3,*temp4; 
       temp= start_ptr;
       cout<<endl;
       int id,id1; //count;
       cout<<"enter ID u want to swap "<<endl;
       cin>>id;
       cout<<"enter 2nd ID u want to swap "<<endl;
       cin>>id1; 
       if (start_ptr == NULL)
       {
         cout << "The list is empty!" << endl;
       }
       while(temp!=NULL)
       {
       if(temp->ID=id1)
       { 
           temp2=temp;
           temp=temp->nxt;
       }
       }

       while(temp3!=NULL)
       {
        if(temp3->ID=id1)
        {
            temp4=temp3;
           temp3=temp3->nxt;

        }
       }

     temp->nxt=temp4;
     temp3->nxt=temp2;
     temp->nxt=temp3->nxt;
     temp3->nxt=temp->nxt;
     //temp4->nxt=temp2->nxt;
     //temp2->nxt=temp4->nxt;
     //temp3->nxt=temp2;
    //    temp2->nxt=temp->nxt;
    //    delete temp;
       cout<<endl;
//       cout<<count;
      }

    
void studentrecord:: SearchStudent()
{    studentrecord *temp; 
       temp= start_ptr;
    cout<<endl;
       int id,count=0;
       cout<<"enter student ID u want to search for";
       cin>>id; 
       if (start_ptr == NULL)
         cout << "The list is empty!" << endl;
      else
      {
         while(temp!=NULL )
         {
           if(temp->ID==id)
           {
             cout<<"ID :"<<temp->ID<<endl;
             cout<<"First Name: "<<temp->fname<<endl;
             cout<<"Last Name: "<<temp->lname<<endl;
             cout<<"Programme: "<<temp->programme<<endl;
             cout<<"Year of Study: "<<temp->year_of_study<<endl;
             count++;
           }
       //temp->display_list();
           
            temp = temp->nxt;
         }
       cout<<endl;
       cout<<count;
      }
}


void studentrecord:: DeleteStudent()
{      studentrecord *temp,*temp2; 
       temp= start_ptr;
       cout<<endl;
       int id, count;
       cout<<"enter id u wana delete";
       cin>>id; 
       if (start_ptr == NULL)
       {
         cout << "The list is empty!" << endl;
       }
       if(start_ptr->ID = id)
       {
           temp=start_ptr;
           start_ptr=start_ptr->nxt;
       delete temp;
       }
      else
      {
        while(temp->ID!=id)
           {
               temp2=temp;
             cout<<temp->ID;
             count++;
             temp = temp->nxt;
        }
        temp2->nxt=temp->nxt;
        delete temp;
       cout<<endl;
       cout<<count;
      }
}

void studentrecord::ConditionalDisplay()
{    studentrecord *temp; 
      temp= start_ptr;
      cout<<endl;
      int count=0;
       char lastname[20];
       cout<<"Enter the Last Name to search:   ";
       cin>>lastname; 
       if (temp == NULL)
         cout << "The list is empty!" << endl;
      else
      {
         while(temp!=NULL )
         {
             if(temp->lname==lastname)
             {          
             cout<<endl;
             cout<<temp->lname<<endl;
             cout<<temp->fname<<endl;
             cout<<temp->ID<<endl;
             cout<<temp->ID<<endl;
             cout<<temp->year_of_study<<endl;
            temp=temp->nxt;
           }
       //temp->display_list();
           
            temp = temp->nxt;
         }
       cout<<endl;
       cout<<"There are "<<count<<"maches";
      }
}

void studentrecord:: displayStudentInformation()
{      studentrecord *temp; 
       temp= start_ptr;
    cout<<endl;
       int id,count=0;
       cout<<"enter id to get student information";
       cin>>id;
       if (temp == NULL)
         cout << "The list is empty!" << endl;
      else
   {
         while(temp!=NULL )
   {
    if(temp->ID==id)
    {
      cout<<temp->fname<<endl;
      cout<<temp->lname<<endl;
      cout<<temp->ID<<endl;
      cout<<temp->year_of_study<<endl;
      cout<<endl;
      
      count++; 
    }
       //temp->display_list();
           
      temp = temp->nxt;
   }
   cout<<endl;
  cout<<count;
      }
}
void main()

{  
    //start_ptr = NULL;
    studentrecord l;

     do
    {
     
      cout << "             ______________________________"<<endl;
      cout << "             Please select a choice : " << endl;
      cout << "             ______________________________"<<endl;
      cout << "             0. Exit the program." << endl;
      cout << "             1. register student." << endl;
      cout << "             2. search student." << endl;
      cout << "             3. Swap student postion." << endl;
      cout << "             4. display student information." << endl;
      cout << "             5. display all." << endl;
      cout << "             6. conditional display."<<endl;
      cout << "             7. delete."<<endl;
      cout << "             _______________________________" <<endl << "";
     cin >> khetho;

      switch (khetho)
      {   
          case 1 : l.register_student();
    cout<<" ";system("pause");
              system("cls");

              break;
          case 2 : l.SearchStudent(); break;
          case 3 : l.Swap(); break;
          case 4 : l.displayStudentInformation(); break;
          case 5 : l.display_all();break;
          case 6 : l.ConditionalDisplay();break;
          case 7 : l.DeleteStudent();break;
        }
    }
     while (khetho != 0);
  }

[jimblumberg]

Also posted here.

Jim

[aquilina]

Also posted here.

Jim

actually i didnt get what he saying btw..

[jimblumberg]

Then why didn't you ask him to explain himself better? Why post to another forum when you're already getting answers?

Myself, if I were to try to answer the question, I would tell you to tell me what kind of structure you think the program is using. But since I don't care to answer your question I don't expect any answer.

Jim

[aquilina]

Yea i already asked.. Since hes taking long time to answer me and i tried to move other forum to get different way of explaination. Different ppl have his own way to explain. Thats why i try to posted it at here instead waiting for his reply. Ah ok since you dont want to answer it. Maybe i should tried other forum then. Thank.

[Elysia]

The only thing I am going to say is that the code is garbage, an eyesore. In fact, I'd call it C code, and not C++ code.
What do you want to do with it, anyway?

[rags_to_riches]

Looks like it was copied from here.

EDIT: Ah, it's a linked list.

[Elysia]

Oh, so a professor who writes garbage code that students need to understand and explain? Great...
Maybe this professor should just stick with C since he/she is so familiar with it >_<

[Cat]

Wow, is that really a teacher's code?

Get out of that class. Seriously, this code is awful. There are no less than four absolute showstopper errors in one method alone (two infinite loops, a dereference of an uninitialized pointer, and a sequence of operations that leaves what's left of the list in an invalid state).

It looks like a linked list implementation done by someone who doesn't know how a linked list works.

[rcgldr]

Its using binary tree, queue, tree or vector or others?

As already posted it's a single linked list (the structures have a "next" pointer"). A doubly linked list would have a previous and a next pointer. A binary tree is made of structures that include "node" structures that have two pointers, "left" and "right" that link to "sub-trees". A queue normally mean just about any structure or method that is first in first out, such as a circular buffer, but it can also be a linked list. A tree is a general form of a binary tree. A vector is essentially the same as an array, it's accessed via indexes or pointers.