Solution to Reverse a doubly linked list

readme.md

Reverse a doubly linked list

https://www.hackerrank.com/challenges/reverse-a-doubly-linked-list/problem?h_r=next-challenge&h_v=zen

sol.cpp

#include <bits/stdc++.h>

using namespace std;

class DoublyLinkedListNode {
    public:
        int data;
        DoublyLinkedListNode *next;
        DoublyLinkedListNode *prev;

        DoublyLinkedListNode(int node_data) {
            this->data = node_data;
            this->next = nullptr;
            this->prev = nullptr;
        }
};

class DoublyLinkedList {
    public:
        DoublyLinkedListNode *head;
        DoublyLinkedListNode *tail;

        DoublyLinkedList() {
            this->head = nullptr;
            this->tail = nullptr;
        }

        void insert_node(int node_data) {
            DoublyLinkedListNode* node = new DoublyLinkedListNode(node_data);

            if (!this->head) {
                this->head = node;
            } else {
                this->tail->next = node;
                node->prev = this->tail;
            }

            this->tail = node;
        }
};

void print_doubly_linked_list(DoublyLinkedListNode* node, string sep, ofstream& fout) {
    while (node) {
        fout << node->data;

        node = node->next;

        if (node) {
            fout << sep;
        }
    }
}

void free_doubly_linked_list(DoublyLinkedListNode* node) {
    while (node) {
        DoublyLinkedListNode* temp = node;
        node = node->next;

        free(temp);
    }
}

// Complete the reverse function below.

/*
 * For your reference:
 *
 * DoublyLinkedListNode {
 *     int data;
 *     DoublyLinkedListNode* next;
 *     DoublyLinkedListNode* prev;
 * };
 *
 */
DoublyLinkedListNode* reverse(DoublyLinkedListNode* head) {
     auto temp = head; 
    while(head != nullptr)
    {
        temp = head->next;
        head->next = head->prev;
        head->prev = temp;
        if(temp==nullptr) return head;
        head=temp;
    }
    return head; 
}

int main()