Linked List | Data Structures

#include<iostream>
#include<conio.h>
using namespace std;



struct stack
{
 int data;
 struct stack *next;
}*start=NULL;

typedef struct stack node;

void create();
void insert_atbeg();
void insert_after();
void deletenode();
void display();
void reverse(node *);



main()
{

   int choice,ch;
   do
  {
   cout<<"\n 1. create";
   cout<<"\n 2. insert ";
   cout<<"\n 3.delete";
   cout<<"\n 4. display";
   cout<<"\n 5.reverse";
   cout<<"\n Enter the choice :";
   cin>>choice;
  
  switch(choice)
 
  {
    case 1 :  create();
              break;
   
    case 2 :
             cout<<"\n 1.Insert at beginning";
             cout<<"\n 2. Insert after a node";
             cout<<"\n Enter choice ";
             cin>>ch;
             switch(ch)
             { case 1 : insert_atbeg();
                        break;
               case 2 : insert_after();
                        break; 
              default : break;
              } 
             break;
   
    case 3 :  deletenode();
              break;
    case 4 : display();
             break;
    case 5 : reverse(start);
             break;
    default : cout<<"\n Wrong choice! ";
              break;
  }

 }while(choice>0&&choice<5);
getch();

}

void create()
{  

  char choice;
  do
 {
  node *temp,*first;
  temp=new node;
  cout<<"\n Enter the item to insert ";
  cin>>temp->data;
  temp->next=NULL;
  if(start==NULL)
   {  start=temp;
      first=start;
   }  
  else
   { 
     first->next=temp;
     first=temp;
   }
  cout<<"\n Do you want to enter more node ?(y/n)";
  cin>>choice;
 }while(toupper(choice)=='Y');
       
}

void insert_atbeg()
{ node *temp;
  temp=new node;
  cout<<"\n Enter the data :";
  cin>>temp->data;
  temp->next=start;
  start=temp;
}
 
void insert_after()
{
  int location;
  display();
  cout<<"\n Enter the location to insert :";
  cin>>location;
  node *temp,*first;;
  first=start;
  temp = new node;
 
  cout<<"\n Enter the data item :";
  cin>>temp->data;
  while(first!=NULL)
  {
     if(first->data==location)
       {
         if(first->next==NULL)
           { first->next=temp;
             temp->next=NULL;
           }
         else
          { temp->next=first->next;
            first->next=temp;
          }
      }
     first=first->next;
  }
}

void deletenode()
{
  node *temp,*c;
  int item;
 
  if(start==NULL)
    cout<<"\n No item to delete ";
  else
   {
     temp=start;
     cout<<"\n Enter the node to delete ";
     cin>>item;
     if(temp->data==item)
      {
        if(temp->next==NULL)
         {
           delete temp;
           start=NULL;
         }
       else
        { 
           start=start->next;
           delete temp;
          
        }
      }
     else
      {
         while(temp->next!=NULL)
            {
              if(temp->next->data==item)
                {
                  c=temp->next;
                  temp->next=temp->next->next;
                  delete c;
                  break;
                }
   
              temp=temp->next;
            }

      }
   }

}
void display()
{
  node *temp;

 if(start==NULL)
    cout<<"\n No item to display ";
else
 { cout<<"\n";
   temp=start;
   while(temp!=NULL)
   {
     cout<<" "<<temp->data;
     temp=temp->next;
   }
 
 }
}
 
void reverse(node *t)
{
if(t==NULL)
return;
reverse(t->next);
printf("%d",t->data);       
}