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



class Student // Structure Student
	{
	public:
		string sname; // Data Members
	    string department;
	    string major;
	    int ID;
		Student *nxt;
	};
class StudentList
{
	friend ostream &operator<<(ostream &, const StudentList&);
public:
	StudentList();//Default Constructor
	void insert(int &, string , string , string );
	void print();
	void clearlist();
	void removelist(int &);
	void mergelist( Student, Student);
	Student *start;
	Student *current;
	
	
};
StudentList::StudentList()
{
	start = 0;
	current = 0;
}
ostream &operator<<(ostream &output, const StudentList &a)
{
	Student*temp;
	
	temp = a.start;
     if (temp == 0)
        cout << "empty!" << endl;
     else
		cout << "ID" << setw(9) << "sname" << setw(13) << "department" << setw(9) << "major" << endl;
       { while (temp != 0)

		{  // Display decurrents for what temp points to
			
          output << temp->ID << setw(9) << temp->sname << setw(13) << temp->department << setw(9) << temp->major << endl;    
	      temp = temp->nxt;

		}
	   
	   }
	   return output;
}
void StudentList::insert(int &idx, string snamex, string departmentx, string majorx) // Add and Insert List
{
	Student *temp; Student *temp2 = 0; Student *temp3 = 0; // temp pointers
	
	temp = new Student;
	(temp->sname)=snamex;
	(temp->major)=majorx;
	(temp->department)=departmentx;
	(temp->ID) = idx;
	(temp->nxt) = NULL;

	if (start == 0 || start->ID>=temp->ID) 
	{
		temp->nxt = start; 
		start = temp;
		current = start;
	}
	else
	{
		temp2 = start;
		while(temp2 != 0 && (temp2->ID < temp->ID))
		{
			temp3 = temp2;
			temp2 = temp2->nxt;
		}
		//While ends with temp2 having an ID >= temp and temp3 having an ID < temp
		if (temp3 != 0)
		 temp3->nxt = temp;

	if (temp2 != 0)
		 temp->nxt = temp2;

		
	}
}

	void StudentList::removelist(int &) 
	{
		long int idx;
		Student *temp;
		Student *temp2 = 0;

		cout<<"Enter the ID# that you want to get deleted: ";
		cin>>idx;

		temp = start;
		while (temp->ID != idx)
		{
			temp2 = temp;
			temp = temp->nxt;
		}
		if(temp != NULL)
		{
			if (temp == start)
			{
				start = start->nxt;
				delete(temp);
			}
			else
			{
				temp2->nxt=temp->nxt;
				delete(temp);
			}
		}
	}

	void StudentList::clearlist() // delete list
	{
		while(start != 0)
			removelist(start->ID);
	}



/*void StudentList::mergelist(Student stud1,Student stud2) 
	// (There seems to be syntex erros in this..)
	{
		Student *temp;
		

		for(temp = stud1->start; temp != 0 ; temp = temp->nxt)
			insert(temp->ID,temp->sname,temp->department,temp->major);
		for(temp = stud2->start; temp != 0 ; temp = temp->nxt)
			insert(temp->ID,temp->sname,temp->department,temp->major);
	}
	
*/






int main()
{

int choice;
StudentList student;
StudentList student1;
StudentList student2;

do
{
     	cout
		    <<	"1: Add a student to List1\n"
    		<<  "2: Delete student from StudentList1\n"
			<<  "3: Print StudentList1\n" 
			<<  "4: Add a student to StudentList2\n"
			<<	"5: Delete a record from StudentList2\n"
			<<  "6: Print StudentList2\n" 
			<<  "7: Merge StudentList1 and StudentList2 into a single list and display result\n"
			<<  "8: Exit\n"
			<< endl;
		cin >> choice;
		cout << endl;
        
				int idx;
				string snamex, departmentx, majorx;
            switch (choice)
            {
			case 1:
				cout << "Input ID : ";
				cin >> idx;
				cout << "Input sname : ";
				cin >> snamex;
				cout << "Input department : ";
				cin >> departmentx;
				cout << "Input major : ";
				cin >> majorx;
				student.insert(idx, snamex, departmentx, majorx);
				break;
			case 2:
				student.removelist(idx);
				break;
			case 3:
				cout << student;
				break;
			case 4:
				cout << "Input ID : ";
				cin >> idx;
				cout << "Input sname : ";
				cin >> snamex;
				cout << "Input department : ";
				cin >> departmentx;
				cout << "Input major : ";
				cin >> majorx;
				student1.insert(idx, snamex, departmentx, majorx);
				break;
			case 5:
				student1.removelist(idx);
				break;
			case 6:
				cout << student1;
				break;
			case 7:
				//student2.clearlist();
				//student2.mergelist(student,student1);
			case 8:
				break;
			default:
			   cout << "Wrong option!" << endl;
				break;         
            }
       
	}while(choice!=8);
	return 0;
		}

string sname; // Data Members
string department;
string major;
int ID;

Student* student;
Student* next;

StudentNode* head;
StudentNode* current;

Student* student;
StudentNode* next; // not Student* next;