Single LinkedList – C++.

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Example – Single LinkedList

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#include <iostream.h>

       class List

      {

           private:

              int n;

              List *next,*head,*ptr;

           public:

              List()

                   {

                        next=head=ptr=NULL;

                   }

              void Add();

              void Disp();

              void Del();

              void Ins();

              void Reverse();

  };

  void List::Add()

      {

           List *temp;

           temp=new List();

           cout<<"\n\tEnter Data : ";

           cin>>temp->n;

           temp->next=NULL;

           if(head==NULL)

              {

                   ptr=head=temp;

              }

           else

              {

                   ptr->next=temp;

                   ptr=temp;

              }

      }

  void List::Disp()

      {

           List *pr;

           cout<<"\n\tList .. ";

           for(pr=head;pr;pr=pr->next)

              {

                   cout<<pr->n<<" ";

              }

      }

  void List::Del()

      {

           List *pr,*pr1;

           int num;

          cout<<"\n\tEnter No. to Delete ";

           cin>>num;

           for(pr=head;pr;pr=pr->next)

              {

                   if(pr->n==num)

                        {

                            break;

                        }

                   pr1=pr;

              }

           if(pr==head)

              {

                   head=head->next;

              }

           else if(pr==NULL)

              {

                   cout<<"\n\tNumber not Found!!\n";

              }

           else

              {

                   pr1->next=pr->next;

              }

           delete(pr);

      }

  void List::Ins()

      {

           List *temp,*ptr1;

           int num,pos,i=0;

           cout<<"\n\tEnter Number to Add : ";

           cin>>num;

           cout<<"\n\tEnter Position : " ;

           cin>>pos;

           temp=new List();

           temp->next=NULL;

           temp->n=num;

           for(ptr1=head;ptr1->next!=NULL;ptr1=ptr1->next)

              {

                   i++;

                   if(i==pos)

                        {

                            break;

                        }

              }

           if(ptr1==head)

              {

                   temp->next=head;

                   head=temp;

              }

           else if(ptr1->next==NULL)

              {

                   ptr1->next=temp;

              }

           else

              {

                   temp->next=ptr1->next;

                   ptr1->next=temp;

              }

      }

  void List::Reverse()

      {

           List *ptr1,*ptr2,*ptr3;

           ptr1=head;

           ptr2=NULL;

           while(ptr1!=NULL)

              {

                   ptr3=ptr2;

                   ptr2=ptr1;

                   ptr1=ptr1->next;

                   ptr2->next=ptr3;

              }

           head=ptr2;

      }

  int main()

      {

           int ch=0;

           List L;

           while(ch<6)

              {

                   cout<<"\n\t1. Add ";

                   cout<<"\n\t2. Display";

                   cout<<"\n\t3. Delete";

                   cout<<"\n\t4. Insert ";

                   cout<<"\n\t5. Reverse";

                   cout<<"\n\t6. Exit ";

                   cout<<"\n\tEnter a Choice ";

                   cin>>ch;

                   switch(ch)

                        {

                            case 1:L.Add();break;

                            case 2:L.Disp();break;

                            case 3:L.Del();break;

                            case 4:L.Ins();break;

                            case 5:L.Reverse();break;

                            case 6:cout<<"\n\t\tBye ....";break;

                            default:cout<<"\n\t\tInvalid Choice ";

                        }

              }

           return 0;

      }