OPERATIONS ON LINKED LIST

#include<iostream>

using namespace std;

#include<conio.h>

struct node

{

int data;

node *link;

};

node *start=NULL;

node *tail=NULL;

void create();

void display();

void insert(int);

void Delete(int);

int main()

{

int ch;

int position,item;

do

{

cout<<"\n Enter 1 to create"<<"\n"<<"Enter 2 to display "<<"\n Enter 3 to search"<<"\nEnter 4 to insert"<<"\n Enter 5 to delete :"<<"\n";

cin>>ch;

if(ch==1)

{

create();

}

else if(ch==2)

{

display();

}

else if(ch==4)

{

cout<<"Enter the position";

cin>>position;

insert(position);

}

else if(ch==5)

{

cout<<"enter the item";

cin>>item;

Delete(item);

}

}

while(ch==1||2||3||4||5);

getch();

return 0;

}

void display()

{

node *k;

if (start==NULL)

{

cout<<"list is empty";

}

else

{

for(k=start;k!=NULL;k=k->link)

{

cout<<"\n"<<k;

cout<<"\t"<<k->data;

cout<<"\t"<k->link;

}

}

}

void create()

{

node *p,*q;

p=new node;

cout<<"enter data of node";

cin>>p->data;

p->link==NULL;

if(start==NULL)

{

start=p;

tail=p;

}

else

{

tail->link=p;

tail=p;

}

}

void insert(int position)

{

node *p,*q;

p=new node;

cout<<"enter data part";

cin>>p->data;

p->link=NULL;

if(position==1)

{

p->link=start;

start=p;

}

else

{

q=start;

int k=1;

while((q->link!=NULL ) && (k!=position-1))

{

k++;

q=q->link;

}

}

}

void Delete(int item)

{

if(start==NULL)

{

cout<<"case of underflow,it can not be deleted";

}

else

{

node *p,*pp;

if( start ->data==item)

{

p=start;

start=start ->link;

}

else

{

p=start;

while((p != NULL)&& (p ->data != item) )

{

pp =p;

p=p -> link;

}

if(p==NULL)

{

cout<<"can be delete";

}

else

{

pp -> link = p -> link;

}

}

delete p;

}

}