#include <cstdlib>
#include <iostream>

using namespace std;

typedef int Data;

class CLNode
{
int element;
CLNode*next;
CLNode(int evalue,CLNode*nvalue){
     element=evalue;
     next=nvalue;
     }
     friend class CircularLinkedList;
     };
    
 class CircularLinkedList
 {
       CLNode *ListData;
   public:
   CircularLinkedList();  
  ~CircularLinkedList();
     bool IsEmpty();
      void MakeEmpty();
      void InsertItem(int item);
      bool FindItem(int key);
      void DeleteItem(int item);
      void Print();
};


CircularLinkedList::CircularLinkedList()
{
                ListData=NULL;
}

CircularLinkedList::~CircularLinkedList()
{
    MakeEmpty();
}

void CircularLinkedList::MakeEmpty(){
     CLNode*location=ListData;
     while(ListData->next!=ListData){
           location=ListData->next;
           ListData->next=location->next;
           delete location;
           }
           if (ListData->next==ListData){
               location=ListData;
               ListData=NULL;
               delete location;
               }
}

bool CircularLinkedList::IsEmpty(){
         if (ListData==NULL)
             return true;
         return false;
}
void CircularLinkedList::InsertItem(int item){
      if (IsEmpty()==true){
      CLNode*location=new CLNode(item,location);
      location->next=location;
      ListData=location;
      }
      else{
      CLNode*location=new CLNode(item,ListData->next);
      ListData->next=location;
      ListData=location;
      }
}
void CircularLinkedList::Print(){
     if (IsEmpty()==false){
       CLNode*location=ListData;
       cout<<"CircularLinkedList:";
     if (location==ListData){
         cout<<location->element<<"->";
         location=location->next;
         }
         while (location!=ListData){
               cout<<location->element<<"->";
               location=location->next;
               }
               cout<<endl;
               }else
               cout<<"CircularLinkedList is empty"<<endl;
}
bool CircularLinkedList::FindItem (int key){
       if (IsEmpty()==true){
           CLNode*location=ListData;
           while (location->element!=key && location->next==ListData)
                   {
                      location=location->next;
                   }
                      if (location->element==key)
                      return true;
                      return false;
                   }else
                    return false;
                   }
void CircularLinkedList::DeleteItem(int Item){
     if (IsEmpty()==false){
                           CLNode*predLoc=ListData;                                            
                           CLNode*location=ListData;
                           while (location->element!=Item && location->next!=ListData){
                                 predLoc=location;
                                 location=location->next;
                                 }
                                 if (location->next==ListData)
                                 cout<<"ugugdsun element baikhgvi bna"<<endl;
                                 else
                                 if (location->element==Item){
                                 if (location==ListData){
                                    while(predLoc->next!=location)
                                    predLoc=predLoc->next;
                                    ListData=ListData->next;
                                    }
                                    predLoc->next=location->next;
                                    delete location;
                                    }
                                    }else
                                    cout<<"CircularLinkedList is empty"<<endl;
}                                                                            
int main(int argc, char *argv[])
{
    CircularLinkedList List;
    List.InsertItem(10);
    List.InsertItem(15);
    List.InsertItem(5);
    List.InsertItem(25);
    List.Print();
   
    bool f = List.IsEmpty();
    cout<<f<<endl;
   
    List.MakeEmpty();
    List.Print();
   
    List.InsertItem(2);
    List.InsertItem(5);   
    List.InsertItem(10);       
    List.Print();
   
    bool m = List.FindItem(5);
    cout<<m<<endl;
   
   
    List.DeleteItem(10);
    List.Print();
   
   
    system("PAUSE");
    return EXIT_SUCCESS;
}

SinglyLinkedList

#include <cstdlib>
#include <iostream>

using namespace std;
class SLNode{
int element;

SLNode *next;

SLNode(int evalue, SLNode *nvalue){
            element=evalue; next=nvalue;
            }
            friend class SinglyLinkedList;
            };
class SinglyLinkedList
{
      SLNode *head;
      SLNode *tail;
    public:
           SinglyLinkedList();
           ~SinglyLinkedList();
           bool IsEmpty();
           void MakeEmpty();
           int First();
           int Last();
           void InsertFirst(int item);
           void InsertLast(int item);
           void InsertBefore(int key, int item);
           void InsertAfter(int key, int item);
           void InsertPosition(int pos, int item);
           bool FindItem(int item);
           void DeleteFirst();
           void DeleteLast();
           void DeleteBefore(int item);
           void DeleteAfter(int item);
           void DeletePosition(int pos);
           void DeleteItem(int item);
           int Count();
           void Print();
           };
          
          
           SinglyLinkedList::SinglyLinkedList(){
           head=tail=NULL;
           }
           SinglyLinkedList::~SinglyLinkedList(){
           MakeEmpty();
           }
           void SinglyLinkedList::MakeEmpty()
           {                                                                          
                SLNode *curr=NULL;
                while(head !=NULL){
                      curr=head;
                      head=head->next;
                      delete curr;
           }
            tail=NULL;
          }
          bool SinglyLinkedList::IsEmpty(){
               if(head==NULL && tail==NULL)
                    return true;
                   return false;
          }
          void SinglyLinkedList::InsertFirst(int item)
          {
               SLNode *curr=new SLNode(item, head);
               if(IsEmpty()==true)
                  tail=curr;
                  head=curr;
          }
          void SinglyLinkedList::InsertLast(int item)
          {
               SLNode *curr=new SLNode(item, NULL);
               if(IsEmpty()==true)
                  head=curr;
               else
                  tail->next=curr;
                  tail=curr;
          }
          void SinglyLinkedList::InsertBefore(int key, int item){
               SLNode *prevcurr=NULL;
               SLNode *nextcurr=head;
               if(IsEmpty()==false){
                    while(nextcurr->element!=key && nextcurr!=NULL){
                          prevcurr=nextcurr;
                          nextcurr=nextcurr->next;
          }
                          if(nextcurr==NULL)
                             cout<<"ugugdsun element oldsongvi";
                          if(nextcurr->element==key) {
                             SLNode *curr=new SLNode(item, nextcurr);
                             prevcurr->next=curr;
                          }
             }
             else
                cout<<"SinglyLinkedList is empty"<<endl;
          }
          void SinglyLinkedList::InsertAfter(int key, int item) {
               SLNode *prevCurr=NULL;
               SLNode *nextCurr=head;
               if(IsEmpty()==false){
                    while(prevCurr->element!=key && nextCurr!=NULL){
                    prevCurr=nextCurr;
                    nextCurr=nextCurr->next;
          }   
               if(nextCurr==NULL)
                  cout<<"ugugdsun element oldsongvi";
               if(prevCurr->element==key){
                  SLNode *curr=new SLNode(item, nextCurr);
                  prevCurr->next=curr;
               }                           
            }
            else
                cout<<"SinglyLinkedList is empty"<<endl;
          }
          void SinglyLinkedList::InsertPosition(int pos, int item)
          {
               if(IsEmpty()==false){
                  SLNode *prevCurr=NULL;
                  SLNode *nextCurr=head;
                  int i=1;
                  while(i!=pos && nextCurr!=NULL){
                       prevCurr=nextCurr;
                       nextCurr=nextCurr->next;
                       i++;
               }
               if(nextCurr==NULL)
                      cout<<"bairlal buruu";
               if(i==pos) {
                   SLNode *curr=new SLNode(item, nextCurr);
                   prevCurr->next=curr;
               }
            }
            else
                cout<<"SinglyLinkedList is empty"<<endl;
          }
          void SinglyLinkedList::Print(){
               if(IsEmpty()==false){
                    SLNode *curr=head;
                    cout<<"SinglyLinkedList:";
                    while(curr!=NULL){
                        cout<<curr->element<<"->";
                        curr=curr->next;
                    }
               }
               else
                    cout<<"SinglyLinkedList is empty"<<endl;
          }                                               
          bool SinglyLinkedList::FindItem(int key){
               if(IsEmpty()==false){
               SLNode *curr=head;
               while(curr!=NULL && curr->element!=key){
                     curr=curr->next;
              }
               if(curr->element==key) return true;
               return false;
               }
               else
                return false;
          }
          int SinglyLinkedList::Count(){
              if(IsEmpty()==false){
                   SLNode *curr=head;
                   int counter=0;
                   while(curr!=NULL){
                         counter++;
                         curr=curr->next;
                       }
                        return counter;
                   }
                   else
                        return 0;
          }
          int SinglyLinkedList::First(){
               if(IsEmpty()==true)
                  cout<<"SinglyLinkedList is empty";
                 return head->element;
          }
          int SinglyLinkedList::Last(){
               if(tail==NULL)
                  cout<<"SinglyLinkedList is empty";
                  return tail->element;
          }
          void SinglyLinkedList::DeleteFirst(){
               if(IsEmpty()==false){
                    SLNode *curr=head;
                    head=curr->next;
                    delete curr;
               }
               else
                    cout<<"SinglyLinkedList is empty"<<endl;
          }
          void SinglyLinkedList::DeleteLast(){
               if(IsEmpty()==false){
                    SLNode *prevCurr=NULL;
                    SLNode *curr=head;
                    while(curr!=tail)
                    {
                     prevCurr=curr;
                     curr=curr->next;
                    }
                if(curr==tail){
                    prevCurr->next=curr->next;
                    tail=prevCurr;
                   }
                    delete curr;
                }
                else
                    cout<<"SinglyLinkedList is empty"<<endl;
          }
          void SinglyLinkedList::DeleteBefore(int key){
               if(IsEmpty()==false){
                    SLNode *prevCurr=NULL;
                    SLNode *curr=NULL;
                    SLNode *nextCurr=head;
                    while(nextCurr!=NULL && nextCurr->element!=key)
                    {
                          prevCurr=curr;
                          curr=nextCurr;
                          nextCurr=nextCurr->next;
                    }
                    if(nextCurr==NULL)
                       cout<<"key element oldsongvi"<<endl;
                    if(nextCurr==head)
                       cout<<"key elementiin umnu element bhgvi bna"<<endl;
                  else if(nextCurr->element==key){
                       if(curr==head)
                          head=nextCurr;
                       else
                          prevCurr->next=nextCurr;
                       delete curr;
                  }
                }
                 else
                      cout<<"SinglyLinkedList is empty"<<endl;
          }
          void SinglyLinkedList::DeleteAfter(int key){
               if(IsEmpty()==false){
                    SLNode *prevCurr=NULL;
                    SLNode *curr=head;
                    while(curr!=NULL && prevCurr->element!=key)
                    {
                      prevCurr=curr;
                      curr=curr->next;
                    }
                    if(curr==NULL)
                      cout<<"key element oldsongvi"<<endl;
                    if(prevCurr==tail)                                                                                                                                                  
                      cout<<"key elementiin hoino element bhgvvi bna"<<endl;
               else if(prevCurr->element==key){
                    prevCurr->next=curr->next;
                    delete curr;
               }
            }
             else
                cout<<"SinglyLinkedList is empty"<<endl;
          }
          void SinglyLinkedList::DeleteItem(int key){
               if(IsEmpty()==false){
                    SLNode *prevCurr=NULL;
                    SLNode *curr=head;
                    while(curr!=NULL && curr->element!=key)
                    {
                      prevCurr=curr;
                      curr=curr->next;
                    }
                if(curr==NULL)
                      cout<<"key element oldsongvi"<<endl;
                if(curr==tail)
                   tail=prevCurr;
                if(curr==head)
                   head=prevCurr;
                if(curr->element==key){
                   prevCurr->next=curr->next;
                   delete curr;
                }
               }
                else
                     cout<<"SinglyLinkedList is empty"<<endl;
          }
          void SinglyLinkedList::DeletePosition(int pos){
               if(IsEmpty()==false){
                    int i=0;
                    SLNode *prevCurr=NULL;
                    SLNode *curr=head;
                    while(curr!=NULL && i!=pos)
                    {
                          prevCurr=curr;
                          curr=curr->next;
                          i++;
                    }
                    if(curr==NULL)
                       cout<<"bairlal oldsongvi"<<endl;
                    if(i==pos)
                    if(curr==head)
                       head=curr->next;
                    else
                       prevCurr->next=curr->next;
                    if(curr==tail)
                       tail=prevCurr;
                       delete curr;
                    }
             
               else
                     cout<<"SinglyLinkedList is empty"<<endl;
          }                                                                                                                                                                                                                                                                                                                           


int main(int argc, char *argv[])
{
    SinglyLinkedList list;
    list.InsertFirst(21);
    list.InsertFirst(24);
    list.Print();


    system("PAUSE");
    return EXIT_SUCCESS;
}