Single Linked List Program

#include<iostream>

using namespace std;

class structures

{

        struct std

        {

        int rno;

        char name[20];

        struct std*link;

        }*head;

        int size;

        public:

        void getdata();

        void display();

        void insertbegin();

        void insertmiddle();

        void insertend();

        void delbegin();

        void dellast();

        void delmiddle();

        void search();

        structures()

        {

        head=NULL;

        }

};

void structures::getdata()

{

        struct std*t;

   cout<<"enter size \n";

   cin>>size;

   for(int i=0;i<size;i++)

   {

        t=new std;

        cout<<"\nenter roll no ";

        cin>>t->rno;

        cout<<"\nName is ";

        cin>>t->name;

        if(head==NULL)

        {

                 t->link=NULL;

                 head=t;

        }

        else

        {

                 t->link=head;

                 head=t;

        }

    }

}

void structures::insertbegin()

{

 struct std*t;

 t=new std;

 cout<<"\n Enter rollno ";

 cin>>t->rno;

 cout<<"Name is ";

 cin>>t->name;

 if(head==NULL)

 {

  head=t;

 t->link=NULL;

 }

 else

 {

  t->link=head;

  head=t;

 }

}

void structures::insertmiddle()

{

        int no;

struct std*t;

t=new std;

cout<<"\n enter roll no";

cin>>t->rno;

cout<<"\nName ";

cin>>t->name;

cout<<"enter roll no after which the node to be inserted\n";

cin>>no;

std*p;

p=new std;

p=head;

while(p->rno!=no&p!=NULL)

p=p->link;

if(p!=NULL)

 {

 t->link=p->link;

 p->link=t;

 }

}

void structures::insertend()

{

 struct std*t;

 t=new std;

 cout<<"\n Enter Roll no ";

 cin>>t->rno;

 cout<<"\nName is ";

 cin>>t->name;

 if(head==NULL)

 {

  head=t;

  t->link=NULL;

 }

 else

 {

  std*p;

 p=new std;

 p=head;

 while(p->link!=NULL)

 p=p->link;

 p->link=t;

 t->link=NULL;

 }

}

void structures::delbegin()

{

 struct std*t;

 t=new std;

t=head;

head=head->link;

delete(t);

}

void structures::dellast()

{

 struct std*p,*t;

 p=new std;

 t=new std;

 p=head;

 while(p->link->link!=NULL)

 p=p->link;

 t=p->link;

 p->link=NULL;

 delete(t);

}

void structures::delmiddle()

{

 int no;

 cout<<"enter rno of node to be deleted";

 cin>>no;

 std*p,*t;

 p=head;

 while(p->link->link!=NULL&p->link->rno!=no)

 p=p->link;

 t=p->link;

 p->link=t->link;

 delete(t);

}

void structures::search()

{

 int r;

 std*p;

 p=new std;

 p=head;

 cout<<"enter rno of node to search ";

 cin>>r;

 while(p->rno!=r&p->link!=NULL)

 p=p->link;

if(p==NULL)

 {

 cout<<"\nElement not found \n";

 }

 else

 {

 cout<<"node is "<<p->name<<"\t"<<p->rno;

 }

}

void structures::display()

{

 std*p;

 p=new std;

 p=head;

 cout<<"\nStudent details are\n";

 while(p!=NULL)

 {

  cout<<"\nRoll No is "<<p->rno;

  cout<<"\n Name is "<<p->name;

  p=p->link;

 }

}

int main()

{

 structures ob;

 ob.getdata();

 int option,n=1;

while(n==1)

{

 cout<<"\n Enter option";

cout<<"\n1.insert begin\n2.insert middle\n3.insert end\n4.delete begin\n5.delete last\n6.delete  middle\n7.search\n8.display\n0.exit program\n";

cin>>option;

switch(option)

{

 case 1:

 ob.insertbegin();

 ob.display();

 break;

 case 2:

 ob.insertmiddle();

 ob.display();

 break;

 case 3:

 ob.insertend();

 ob.display();

 case 4:

 ob.delbegin();

 ob.display();

 case 5:

 ob.dellast();

 ob.display();

 case 6:

 ob.delmiddle();

 ob.display();

 case 7:

 ob.search();

 case 8:

 ob.display();

 case 0:

 n=0;

 break;

}

}

}