doubly linked list c++ code
/*
* Doubly linked list implementation in c++.
* operations:
* 1-> Insert at head.
* 2-> print forward.
* 3-> print reverse order.
*/
#include<iostream>
using namespace std;
struct node
{
int data;
node* next;
node* prev;
};
class d_list
{
private:
node* head;
node* GetNewNode(int n)
{
node* newNode = new node();
newNode->data = n;
newNode->next = NULL;
newNode->prev = NULL;
return newNode;
}
public:
d_list()
{
head = NULL;
}
void InsertAtHead(int n)
{
node* temp = GetNewNode(n);
if (head == NULL)
{
head = temp;
return;
}
head->prev = temp;
temp->next = head;
head = temp;
}
void print()
{
node* t = head;
cout << "Forward: ";
while (t!=NULL)
{
cout << t->data << " ";
t = t->next;
}
cout << "\n";
}
void print_reverse()
{
node* t = head;
while (t->next != NULL)
{
t = t->next;
}
//reverse
cout << "reverse: ";
while (t != NULL)
{
cout << t->data << " ";
t = t->prev;
}
cout << "\n";
}
};
int main()
{
d_list l; //object from class doubly list
l.InsertAtHead(1);
l.InsertAtHead(2); //function insert at beginning
l.InsertAtHead(3);
l.print(); //List should print: 3 2 1
l.print_reverse(); //List should print: 1 2 3
return 0;
}