Circuler List

 

#include<iostream>

using namespace std;

class circularlist

{

private:

struct node

{int  element;

node* next;

}*head;

public:

circularlist();

void insert(int element);

int remove(int element);

bool isempty();

void search(int key);

int  sizeoflist();

void display();

~circularlist();};

circularlist::circularlist()

{head=NULL;}

bool  circularlist::isempty()

{if(head==NULL)

return true;

else return false;}

 

void circularlist::insert(int element)

{if(isempty())

{

head=new node;

head->element=element;

head->next=head;

return;

}

node* curr=head;

while(curr->next!=head)

curr=curr->next;

node* t=new node;

t->element=element;

t->next=head;

curr->next=t;

return;

}

void circularlist::search(int key)

{ int count=1;

  if(isempty())

  {cout<<"\n list is empty";return;}node* curr;

curr=head->next;

if(head->element==key){

cout<<"\n element found at::\t"<<count;

return;}

count++;

while(curr!=head)

{if(curr->element==key)

  {

    cout<<"\n element found at::\t"<<count;

    return;

  }

  curr=curr->next;

  count++;

}

cout<<"\n sorry!!!elemet is not present\n";

}

int circularlist::remove(int element)

{

if(isempty())

{

  cout<<"\n list is empty  ";

  return -10000;}

  if(head->element==element)

  {

    if(head->next==head)

    {    int data=head->element;delete head;

    head=NULL;

    return data;}

 

    node*t=head;

  node* curr;

  curr=head;

  head=head->next;

 

  while(curr->next!=t)

  curr=curr->next;

  curr->next=head;

  int data;

  data=t->element;

  delete(t);

  return data;}

  node* curr;

  node* pcurr;

  curr=head->next;

  pcurr=head;

  while(curr!=head)

  {

    if(curr->element==element){

    if(curr->next==head)

    {

      pcurr->next=head;

      int data=curr->element;

      delete(curr);

      return data;

    }

 

    pcurr->next=curr->next;

    int data=curr->element;

    delete(curr);

    return data;

 

  }

  pcurr=curr;

  curr=curr->next;

 

} return -20000;}

void circularlist::display()

{

  if(isempty()){

  cout<<"\n list is empty";return;}

  node *curr;

curr=head;

cout<<"->"<<curr->element<<"->";

curr=head->next;

while(curr!=head)

{cout<<"->"<<curr->element<<"->";

curr=curr->next;}}

int circularlist::sizeoflist()

{ int count=0;if(isempty())

{return 0;

 

}

node* curr=head;

count++;

curr=head->next;

while(curr!=head)

{

  curr=curr->next;

  count++;

}

return count;

}

circularlist::~circularlist()

{

}

int main()

{

  circularlist cl;

  int a,b,c,d,e,f;

  char ch;

  cout<<"\n\t\t******WELCOME TO CIRCULER LIST OPERATION*******\n";

  do

  {cout<<"\t\t\tpress 1 to insert in list\n\t\t\t press 2 to display the list\n\t\t\tpress 3 to remove from lis\n\t\t\tpress 4 to  find the length of the lis\n\t\t\tpress 5 to search an element\n\t\t\t\n";

  cout<<"\n enter your choice\t\t";

  cin>>a;

  switch(a)

  {

    case 1:cout<<"\n enter the element you want to insert\t\t";

    cin>>b;

    cl.insert(b);

    break;

    case 2:cout<<"\n____________________________________________\n";

    cl.display();

    cout<<"\n________________________________________________";

    break;

    case 3:cout<<"\n enter the element you want to delete from list::\t\t";

  cin>>c;

    d=cl.remove(c);

    if(d==-10000)

    cout<<"\n list is empty";

    if(d==-20000)

    cout<<"\n element is not present";

    if(d!=-10000&&d!=-20000)

    cout<<"\n\t\t"<<d<<"has been removed from list";

    break;

    case 5:

    cout<<"\n enter the element you want to find\t\t";

    cin>>e;

    cl.search(e);

    break;

    case 4:

    f=cl.sizeoflist();

    cout<<"\n size of list is\t\t"<<f;

    break;

    default:

    cout<<"\n you selested wromg choice";

 

  }

cout<<"\n do you want to continue if yes press y";

cin>>ch;}

while(ch=='y');

  return 0;

}