Program to demonstrate the operations of doubly linked list
/*
* C++ Program to Implement Doubly Linked List
*/
#include < iostream >
#include < cstdio >
#include< cstdlib >
struct node
{
int info;
struct node *next;
struct node *prev;
}*start;
class double_llist
{
public:
void create_list(int value);
void add_begin(int value);
void add_after(int value, int position);
void delete_element(int value);
void search_element(int value);
void display_dlist();
void count();
void reverse();
double_llist()
{
start = NULL;
}
};
int main()
{
int choice, element, position;
double_llist dl;
while (1)
{
cout< < endl << "----------------------------"<< endl;
cout<< endl << "Operations on Doubly linked list" << endl;
cout<< endl << "----------------------------"<< endl;
cout<< "1.Create Node" << endl;
cout<< "2.Add at begining"<< endl;
cout<< "3.Add after position"<< endl;
cout<< "4.Delete"<< endl;
cout<< " 5.Display"<< endl;
cout<< "6.Quit"<< endl;
cout<< "Enter your choice : ";
cin >> choice;
switch ( choice )
{
case 1:
cout << "Enter the element: ";
cin >> element;
dl.create_list(element);
cout<< endl;
break;
case 2:
cout << "Enter the element: ";
cin >> element;
dl.add_begin(element);
cout<< endl;
break;
case 3:
cout << "Enter the element: ";
cin >> element;
cout << "Insert Element after postion: ";
cin >> position;
dl.add_after(element, position);
cout << endl;
break;
case 4:
if (start == NULL)
{
cout << "List empty,nothing to delete"<< endl;
break;
}
cout << "Enter the element for deletion: ";
cin >> element;
dl.delete_element(element);
cout << endl;
break;
case 5:
dl.display_dlist();
cout << endl;
break;
case 6:
exit(1);
default:
cout<<"Wrong choice"<< endl;
}
getch();
}
// return 0;
}
/*
* Create Double Link List
*/
void double_llist::create_list(int value)
{
struct node *s, *temp;
temp = new(struct node);
temp->info = value;
temp->next = NULL;
if (start == NULL)
{
temp->prev = NULL;
start = temp;
}
else
{
s = start;
while (s->next != NULL)
s = s->next;
s->next = temp;
temp->prev = s;
}
}
/*
* Insertion at the beginning
*/
void double_llist::add_begin(int value)
{
if (start == NULL)
{
cout<<"First Create the list."<< endl;
return;
}
struct node *temp;
temp = new(struct node);
temp->prev = NULL;
temp->info = value;
temp->next = start;
start->prev = temp;
start = temp;
cout<<"Element Inserted"<< endl;
}
void double_llist::add_after(int value, int pos)
{
if (start == NULL)
{
cout<< "First Create the list."<< endl;
return;
}
struct node *tmp, *q;
int i;
q = start;
for (i = 0;i < pos - 1;i++)
{
q = q->next;
if (q == NULL)
{
cout<< "There are less than ";
cout<< pos<<" elements."<< endl;
return;
}
}
tmp = new(struct node);
tmp->info = value;
if (q->next == NULL)
{
q->next = tmp;
tmp->next = NULL;
tmp->prev = q;
}
else
{
tmp->next = q->next;
tmp->next->prev = tmp;
q->next = tmp;
tmp->prev = q;
}
cout<< "Element Inserted"<< endl;
}
/*
* Deletion of element from the list
*/
void double_llist::delete_element(int value)
{
struct node *tmp, *q;
/*first element deletion*/
if (start->info == value)
{
tmp = start;
start = start->next;
start->prev = NULL;
cout<< "Element Deleted" << endl;
free(tmp);
return;
}
q = start;
while (q->next->next != NULL)
{
/*Element deleted in between*/
if (q->next->info == value)
{
tmp = q->next;
q->next = tmp->next;
tmp->next->prev = q;
cout<< "Element Deleted"< < endl;
free(tmp);
return;
}
q = q->next;
}
/*last element deleted*/
if (q->next->info == value)
{
tmp = q->next;
free(tmp);
q->next = NULL;
cout<<"Element Deleted"< < endl;
return;
}
cout<< "Element "<< value<<" not found"<< endl;
}
/*
* Display elements of Doubly Link List
*/
void double_llist::display_dlist()
{
struct node *q;
if (start == NULL)
{
cout<< "List empty,nothing to display" << endl;
return;
}
q = start;
cout<< "The Doubly Link List is :"<< endl;
while (q != NULL)
{
cout<< q- > info<< " < - > ";
q = q->next;
}
cout<<"NULL"<< endl;
}
// end of program