#include#include#include#include#include#include#include#includeusing namespace std;bool check = true;struct node    //structure of node //{ char name20; char discipline20; int rollNo; char section; node *next;}*head,*lastptr;void add()    //Adds record of student//{ node *p; p=new node; cout<<"Enter name of student:"<name); fflush(stdin); cout<<"Enter discipline of student:"<discipline); fflush(stdin); cout<<"Enter Roll Number of student:"<>p->rollNo; fflush(stdin); cout<<"Enter section of student:"<>p->section; fflush(stdin); p->next=NULL; if(check) {  head = p;  lastptr = p;  check = false; } else {  lastptr->next=p;  lastptr=p; } cout<>roll_no; prev=head; current=head; while(current->rollNo!=roll_no) {  prev=current;  current=current->next; } ptr=new node; fflush(stdin); cout<<"Enter name of student:"<name); fflush(stdin); cout<<"Enter discipline of student:"<discipline); fflush(stdin); cout<<"Enter Roll Number of student:"<>ptr->rollNo; fflush(stdin); cout<<"Enter section of student:"<>ptr->section; fflush(stdin); prev->next=ptr; ptr->next=current->next; current->next=NULL; delete current; cout<>roll_no; prev=head; current=head; while(current->rollNo!=roll_no) {  prev=current;  current=current->next; } cout<<" name: "; puts(current->name); cout<<" Roll No:"; cout<rollNo; cout<<" Discipline:"; puts(current->discipline); cout<<" Section:"; cout<section; getch();}void del()    //deletes record of a student//{ node *ptr=NULL; node *prev=NULL; node *current=NULL; int roll_no; cout<<"Enter Roll Number to Delete:"<>roll_no; prev=head; current=head; while(current->rollNo!=roll_no) {  prev=current;  current=current->next; } prev->next = current->next; current->next=NULL; delete current; cout<Press ‘1’ to add New record:”<Press ‘2’ to search a record:”<Press ‘3’ to modify a record:”<Press ‘4’ to delete a record:”<Press ‘5’ to exit:”<