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

struct Employee
{
	//Data
	string name;
	int id;
	string residance;
	int salary;
};

class Node
{
public:
	// Data
	Employee data;
	// The Next Pointer
	Node * next;
	// Constructor
	Node(Employee Object ,Node * ptr = NULL );
};

class List
{
	int size;
	Node * first;
	//Node Obj;
	Node * ptr;
	int counter;
public:
	bool Exist;
public:
	List();
	/************************************
		PreCondition : None
		PostCondition : Linked List is constructed , with head and tail pointing
		to nothing and a size if zero
	************************************/

//Copy Constructor
	List(List&  );
	/************************************
	PreCondition : None
	PostCondition : Linked List is constructed that is similar ( copy ) of the paramter
	Object
		************************************/

// Assignment Operator 
	const List operator = (const List & Obj);

	// Destructor 
	~List();


//Empty: check if the list is empty or not.
	/***** empty operation *****/
	   bool Empty();
	   /*----------------------------------------------------------------------
		 Check if a list is empty.

		 Precondition:  None
		 Postcondition: true is returned if the list is empty, 
			 false if not.
	   -----------------------------------------------------------------------*/

//Search: take an employee object, search for it; if found return the Node name and Salary.

	   void Search (Node obj);
//Insert Sorted: takes an object of the Node type, search for it, 
//				 and if found return without insertion else search for its correct position – 
//				 to keep the list ordered by name- then add it.
	   void InsertSorted (Node obj);

//Insert At Mid: takes an object of Node type, and insert it in the middle of the Node list. 
//		         (The middle is n/2 if odd and n/2+1 if even)
	   void InsertMid (Node obj);

//Remove: takes an Node object, search for it in the list, and if found delete it.
	   
	   void Delete (Node obj);

//Remove mid: delete the Node object found in the middle of the list. 
	   void DeleteMid ();

//Change Salary: takes a salary and employee object,
//		         replace the information for this employee by the information passed as parameter.
	   List ChangeSalary(Node obj , int sal);



//Print All Nodes: that prints all employees information.
	   void Print();

};
#include "Header.h"

	
//Constructor
Node::Node(Employee Object ,Node *p)
{
	data=Object;
	next=p;
}
List::List()
{
	first = NULL;
	size = 0;
	ptr = NULL;
	Exist = false;
}
// Copy Constructor
List::List(List& Orig)
{
	
	if(Orig.size==0) 
	{
		first=NULL ;
		return ;
	}
	ptr = first = new Node (Orig.first->data);
	Node * CopyPtr = Orig.first ;


	while(CopyPtr->next)
	{

		CopyPtr=CopyPtr->next;
		ptr->next=new Node(CopyPtr->data);
		ptr = ptr->next;
	}
	size = Orig.size;
}

// Empty
bool List::Empty()
{
		if (size == 0)
		{
			cout<<"the List Is Empty."<<endl;
			return true;
		}
		else
		{
			cout<<"The List Is Not Empty, It Has "<<size<<" Elements."<<endl;
			return false;
		}
}

 //Search
void List::Search(Node obj)
{
	{
		ptr=first;
		for ( int i=0 ; i<=size ;i++)
		{
			if (ptr->data.name==obj.data.name || ptr->data.id==obj.data.id)
			{
				cout<<"The Employee's Name : "<<obj.data.name<<" The Employee's Salary : "<<obj.data.salary<<endl;
				Exist= true;
			}
			else if (i==size)
			{
				ptr=ptr->next;
			}			
			else
			{
				clog<<"Emloyee Not Found"<<endl;
				Exist= false;
			}
		}
			
	}

}



void List::InsertSorted (Node obj)
//Insert Sorted: takes an object of the Node type, search for it, 
//				 and if found return without insertion else search for its correct position – 
//				 to keep the list ordered by name- then add it.
/* 2wl 2shi mn 3mal if statment w btswi serach 3la 2l object w b3dain 2tha 6l3 mwjood zyo btnsa 2l mwdoo3 
w bt6la3 w 2tha kan msh mwjood bt3mal for loop tdqarn feha 2l 2sma2 
w b3dain bkoun fe counter kol ma ynt8il la Node gdeed be zeed mshan n7keelo 2nsert at postion size plus 1 
w mn thma 
*/
{
	int pos=0;
	Search (obj);
	if (Exist)
	{
		cout<<"The Employee Already Exists."<<endl;
	}
	else
	{
		ptr=first;
		for (int i=0 ; i<=size ; i++ )
		{
			if (ptr->data.name<obj.data.name)
			{
				ptr=ptr->next;
				pos=pos+1;
			}
			else
			{
				if(pos<1||pos>size+1)
				{
					cout<<"Invalid Position!"<<endl;
					return ;
				}
				if(pos==1)
				{
					Node * NFirst = new Node(obj.data,first );
					if(NFirst==NULL) 
						return ;
					size++;
					first = NFirst;
					return ;
				}
				if(pos==size+1)
				{
					Node * NEnd = new Node(obj.data);
					if (NEnd==NULL)
						return ;
					size++;
					if (first==NULL)
						first=NEnd ;
					else
					{
					Node *temp = first ;
					while(temp->next!=NULL)
					{
						temp=temp->next;
					}
					temp->next=NEnd;
					}
					return ;
				}

			ptr = first ;
			for(int i=1;i<pos-1;i++)
			{
				ptr=ptr->next;
			}
			Node * newNode = new Node(obj.data,ptr->next);
			ptr->next=newNode;
			size++;
			}
		}
	}
}


//"size" 3la 2 w mnsweelna solafeh 2tha kan frdi 2w zwji b3dain insert 6beee3i

void List::InsertMid(Node obj)
{
	int pos = 0;
	int x = 0;
	if (size>1)
		x=0;
	else
		x=2;
	switch (x)
	{
	case 0:;
	case 1:
		{
			Node * NFirst = new Node(obj.data,first );
			if(NFirst==NULL) 
				return ;
			size++;
			first = NFirst;
			return ;
		}
	case 2:
		{
			pos=size/2;
			ptr =first ;
			for(int i=1;i<pos-1;i++)
			{
				ptr=ptr->next;
			}
			Node * newNode = new Node(obj.data,ptr->next);
			ptr->next=newNode;
			size++;
		}
	}
}
// Delete
void List::Delete (Node obj)
{
	int pos =0;
	//search and make pos === smthin
	if(size==0)
		return ;
	if(pos>size||pos<1) 
	{
		cout<<"Invalide position !"<<endl;
		return ;
	}
	if(size==1)
	{
		delete first;
		first=NULL;
		size = 0;
		return ;
	}
	if(pos==1)
	{
		Node *toDelete = first;
		first = first->next;
		delete toDelete ;
		return ;
	}

	ptr = first;
	for(int i=1;i<pos-1;i++)
	{
		ptr=ptr->next;
	}
	Node *toDelete = ptr->next;
	ptr->next = toDelete->next;
	delete toDelete ;
	size--;
}

//Delete Mid
void List::DeleteMid()
{
	int pos=0;
	pos=size/2;
	ptr = first;
	for(int i=1 ; i<pos-1 ; i++)
	{
		ptr=ptr->next;
	}
	Node *toDelete = ptr->next;
	ptr->next = toDelete->next;
	delete toDelete ;
	size--;
}

// Print
void List::Print()
{
	for (int i = 0 ; i<=size ;i++)
	{
		cout<<ptr->data.name<<ptr->data.id<<ptr->data.residance<<ptr->data.salary<<endl;
		ptr->next;
	}
}
#include "Header.h"


/*
Q2: An Employee information system must contain data about 
	employees in order to retrive and manupliate data easily and quickly. 
Create a structure for Employee that contains: 
	employee name, employee id, residence and Salary.
 
Create a class linked List so that each node has an object of Employee type.
	The class should support the following operations: 

?	Empty: check if the list is empty or not.
?	Search: take an employee object, search for it; 
		if found return the employee name and Salary.
?	Insert Sorted: takes an object of the employee type, search for it, 
		and if found return without insertion else search for its correct position – 
		to keep the list ordered by name- then add it.
?	Insert At Mid: takes an object of employee type, and insert it in the middle of the employee list. 
		(The middle is n/2 if odd and n/2+1 if even)
?	Remove: takes an employee object, search for it in the list, and if found delete it.
?	Remove mid: delete the employee object found in the middle of the list. 
?	Change Salary: takes a salary and employee object,
		replace the information for this employee by the information passed as parameter.
?	Print All Nodes: that prints all employees information.


	Notes:
1- The Linked List class must contain the constructor, copy constructor, and assignment operator.
*/
void main ()
{

	List HomeWork;
	int x;
	do
	{
		cout << endl;
		cout << "Select one of the following"<<endl;
		cout << "1- Check empty"<<endl;
		cout << "2- Search"<<endl;
		cout << "3- Insert Sorted"<<endl;
		cout << "4- Insert"<<endl;
		cout << "5- "<<endl;
		cout << "6- "<<endl;
		cout << "7- "<<endl;
		cout << "8- Print "<<endl;
		cout << "9- Exit"<<endl;
		cout << "Enter your choice  ";
		cin >> x;
		switch (x)
		{
			case 1:
				{
					//HW.Empty();
				}
			case 2:
				{
					//HomeWork.Search (HomeWork.Obj);
					
				}
			case 3:
				{
					//emp * node = new emp;
					//HomeWork.setme();
				//	node->Do_insert();
					break;					
				};
			case 8:
				{
					break;
				}

			case 9: {cout << "Good bye"; break;}
		}
	}	
	while (x !=9);
}

it Genrates this Error


------ Build started: Project: LinkList_20080171071, Configuration: Debug Win32 ------
Linking...
Main.obj : error LNK2019: unresolved external symbol "public: __thiscall List::~List(void)" (??1List@@QAE@XZ) referenced in function _main
C:\Documents and Settings\Marji\My Documents\Visual Studio 2005\Projects\LinkList_20080171071\Debug\LinkList_20080171071.exe : fatal error LNK1120: 1 unresolved externals
Build log was saved at "file://c:\Documents and Settings\Marji\My Documents\Visual Studio 2005\Projects\LinkList_20080171071\LinkList_20080171071\Debug\BuildLog.htm"
LinkList_20080171071 - 2 error(s), 0 warning(s)
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

Add this to your Header.cpp file:

List::~List()
{
}

or delete this line in Header.h:

~List();

You have a List destructor declared but not implemented, so it's calling it, but not finding it.

Thnx Alot Man it's toos simple but the prigram wont work without it
thnx again ;)

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