// preinitialize the new record's next to null
newstudent -> next = null;
 
student_list * prev = null;
student_list * curr = head;
// while there are more records to look at on the list
while (curr != null)
{
   // should the new record come before the 'current' record in the list?
   if (strcmp(newstudent -> Last_Name, curr -> Last_Name) < 0)
   {
      newstudent -> next = curr;
      break
   }
   prev = curr;
   curr = prev -> next;
}
 
if (prev == null)
   head = newstudent
else
   prev -> next = newstudent

#include <iostream> 
#include < stdlib.h>
using namespace std; 
#define SIZE 100 
 
class student_list 
{ 
public:
	char First_name [SIZE]; 
    char Last_name [SIZE]; 
    int ID; 
    float mid_grade,final_grade;  
    student_list *next; // pointer to next link 
}; 
 
student_list *head=NULL; 
student_list *current;
int option =0;
 
void enter_student (){
 
     student_list *temp,*ptr,*front,*back;
     temp = new student_list; // dynamiclly allocationg       
	 cout << "Enter student first name "<<endl; 
     cin >> temp-> First_name; 
     cout << "Enter student last name "<<endl; 
     cin>> temp-> Last_name; 
     cout<< "please enter student ID "<<endl; 
     cin>>temp->ID; 
     cout<<"please enter midterm grade"<<endl; 
     cin>> temp->mid_grade; 
     cout<<"please enter final grade"<<endl; 
     cin>> temp->final_grade; 
	 temp -> next = NULL;
 
	 if (head == NULL ){
		 head = temp;
 
	 }
	 else {
 
		 front=head;
		 if (front->Last_name > temp->Last_name){
 
			head=temp;
			temp->next=front;
		 }
		 else
			 while ( front->Last_name < temp->Last_name){
				 back=front;
				 front=front->next;
			 }
 
		 }
 
	 }
 
 
void display_lists(){
	student_list *temp;
	temp=head;
	cout<<endl;
	if(temp==NULL)
		cout<<"list is empty!"<<endl<<endl;
 
	else{
 
		while(temp !=NULL){
			cout<<"student name: "<<temp->Last_name;
			cout<<","<<temp-> First_name<<endl;
			cout<<"ID number: "<<temp->ID<<endl;
			cout<<"first midterm grade: "<<temp->mid_grade<<endl;
			cout<<"final exam grade: "<<temp->final_grade<<endl<<endl;
			temp = temp -> next;
		}
		cout<< "LIST ENDED !"<<endl;
	}
}
 
void edit(){
 
     char edit[SIZE];
     student_list *temp;
	 cout<<"please enter the student last name"<<endl;
	 cin>> edit;
 
	 while (edit,temp!=NULL){
          if (stcmp(
          cout<<"enter new student first name"<<endl;
          cin>> temp->First_name;
          cout<<"enter new student last name"<<endl;
          cin>>temp->Last_name;
          cout<<"enter new student ID"<<endl;
          cin>>temp->ID;
          cout>>"enter new first midterm grade"<<endl;
          cin<<temp->mid_grade;
          cout"enter new final grade"<<endl;
          cin>>temp->final_grade;
 
}
 
int main () 
 
{ 
 
	head = NULL;
	cout <<"Welcome to bos3ayed C++ writer company "<<endl; 
	cout << " this program help you to orginzing your student information"; 
	cout<<". first name , last name , ID, first midterm grade, and final"<<endl; 
	cout <<endl<<endl; 
	while ( option != 4){
		cout<< "Choose what do you want to do from this menu (1,2,3,4)"<<endl; 
		cout<<"1) Enter new student"<<endl; 
		cout<<"2) Edit existing student ( serch by name)"<<endl; 
		cout<<"3) Display list "<<endl; 
		cout<<"4) Exit"<<endl; 
		cin>> option;
 
		switch (option){
			case 1 : enter_student();
				break;
			case 3 : display_lists();
				break;
			case 2: edit();
				break;
 
 
 
			 } 
}
return 0;
system("pause");
}