Question

Write a program that create a single linked list and consist of all the necessary functions to do the following

1. Add an element to the list, insertion position can be anywhere in the list (first, last and middle)
2. delete an element from the list, deletion position can be anywhere in the list (first, last and middle)

Note:

You need to add proper documentation to your programs and you need to include the output of each program

C++

Answer 1

#include<iostream>
using namespace std;
//node structure
class node
{
   public :
       int d;
       node *next;
   node(int dd)
   {
       d=dd;
       next=NULL;
   }  

};
//linked list
class single_linkedlist
{
   public:
   node *head,*tail;
   single_linkedlist()
   {
       head=tail=NULL;
   }
   //method to add element to list
   void add(int d)
   {
       if(head==NULL)
       {
           head = new node(d);
           tail=head;  
       }
       else
       {
           tail->next=new node(d);  
           tail=tail->next;
       }
   }
  
   //method to printlist
   void print()
   {
       node *temp=head;
       while(temp!=NULL)
       {
           cout<<temp->d<<"->";
           temp=temp->next;  
       }
       cout<<"\n";
   }
  
  

//recursive method to delete a node at given position
void delete_atpos(node *h,int pos)
{
   if(pos==0)
   {
       if(h==head)
       {
           head=head->next;
       }
      
       return;  
   }
   else
   {
       int i=0;
       node *cur,*prev=NULL;
       cur = h;
       while(i<pos)
       {
           prev=cur;
           cur=cur->next;
           i++;
       }
       if(cur!=NULL)  
       prev->next=cur->next;
       else
       prev->next=NULL;
      
   }
  
}
  
  
  
  
};

int main()
{
   single_linkedlist *d = new single_linkedlist();///creating object
   //creating linked list
   d->add(1);
   d->add(2);d->add(3);d->add(4);
   //testing method 3a
   cout<<"Current list :";
   d->print();

  
   single_linkedlist *dd = new single_linkedlist();///creating object
   //creating linked list
   dd->add(8);
   dd->add(2);dd->add(3);dd->add(1);
   dd->add(7);
   //testing method 3a
   cout<<"Current list :";
   dd->print();
   dd->delete_atpos(dd->head,0);//deleting at head
   dd->print();
  
   dd->delete_atpos(dd->head,3);//deleting at tail
   dd->print();
   dd->delete_atpos(dd->head,1);//deleting in middle
  
   dd->print();
  
   return 0;
}

output:

Current list :1->2->3->4->
Current list :8->2->3->1->7->
2->3->1->7->
2->3->1->
2->1->

Process exited normally.
Press any key to continue . . .