Implementing Linked list Data structure in C++ Example Source Code

How to Implement Linked list Data structure in C++ Example Source Code

#include <iostream.h>
#include <conio.h>
#include <string.h>

class node
 {
   friend class list;
   private:
   int data ;
   node* next ;
   };

class list

 {
   private:
    node* first;
      node* last ;
   public:
    list()
       {
         first =  NULL;
         last  =  NULL;
         }

      void add_node()
       {
         if (first==NULL)

          {
            first =  new node ;
            cout << "\n Enter integer for node: " ;
            cin  >> first->data ;
            first->next = NULL ;
            last  =  first  ;
            }

         else
          {
            node* temp = new node ;
          cout << "\n Enter integer for node: ";
          cin >> temp->data ;
          temp->next = NULL ;
            last->next = temp ;
          last = temp   ;
            }

         }

      void display_all_nodes()
       {
         node* temp = first ;
         int small = temp->data ;
         while(temp != last->next)
           {
           if (temp->data < small)
             small = temp->data ;
           cout << endl << temp->data ;
           temp = temp->next ;
           }
           cout << "\n The smallest number is : " << small ;

         }
   int length() ;

   void remove_a_node_interface() ;

   void remove_a_node(int s) ;

   void add_new_node(node*) ;

   void mixing(list l1,list l2) ;

   int smallest();

   };


void list::remove_a_node_interface()
 {
   cout << "\n Enter data of the node to delete";
   int string;
   cin >> string;
   remove_a_node(string);
   }

void list::remove_a_node(int s)
 {

   node* temp = first;
   node* previous = first ;

while(temp !=last->next)
    {
      if (temp->data==s)
       {
         if(temp==first)
          {
            first = first->next ;
            delete temp ;
            break;
            }

         if(temp==last )
          {
            last = previous ;
            delete temp ;
            break;
            }

         temp = temp->next ;
         delete (previous->next) ;
         previous->next = temp ;
         }

      previous = temp ;
      temp = temp->next ;
      }

    }

int list::length()
 {
   int count = 0;
   node* temp = first ;
   while (temp!= NULL )
    {
      count++;
      temp=temp->next;
      }
   cout << "\n The length of list is: " << count ;
   return count ;
   }


void list::add_new_node(node* helper)
 {
   if (first)
    {
      first = helper ;
      last  = helper ;
      last->next = NULL ;
      }
   else
    {
      last->next= helper ;
      last = helper ;
      last->next=NULL;
      }
   }

void list::mixing(list l1, list l2)
 {
   node* mixer1 = l1.first ;
   node* mixer2 = l2.first ;
   while (mixer1 && mixer2)
    {
      add_new_node(mixer1);
      add_new_node(mixer2);
      mixer1 = mixer1->next;
      mixer2 = mixer2->next;
      }

   while(mixer1)
    {
      add_new_node(mixer1);
      mixer1 = mixer1->next ;
      }

   while(mixer2)
    {
      add_new_node(mixer2);
      mixer2 = mixer2->next;
      }


   }



int list::smallest()
 {
   node* temp = first ;
         int small = temp->data ;
         while(temp != last->next)
           {
           if (temp->data < small)
             small = temp->data ;
           temp = temp->next ;
           }
           cout << "\n The smallest number is : " << small ;

     return small ;
   }




void main()
 {
   list link1;
   list link2;
   list link3;
   link1.add_node();
   link1.add_node();
   link1.add_node();
   link1.add_node();
   link1.add_node();
   link1.display_all_nodes();
   link1.remove_a_node_interface();
   link1.display_all_nodes();
   link1.length();
   link2.add_node();
   link2.add_node();
   link2.add_node();
   link2.add_node();
   link2.add_node();
   link2.display_all_nodes();
   link2.remove_a_node_interface();
   link2.display_all_nodes();
   link2.length();
   //cout << link1.smallest();
   //cout << link2.smallest();
   link3.mixing(link1,link2);
   link3.length();
   link3.display_all_nodes();
   getch();
   }