Compare two linked lists

You’re given the pointer to the head nodes of two linked lists. Compare the data in the nodes of the linked lists to check if they are equal. If all data attributes are equal and the lists are the same length, return 1. Otherwise, return 0.

Example:

Input:  n1=3, list1: 1->2->3->NULL, n2=4, list2: 1->2->3->4->NULL
Output: 0

Approach

C++

#include <bits/stdc++.h>
using namespace std;

class SinglyLinkedListNode
{
public:
    int data;
    SinglyLinkedListNode *next;

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

class SinglyLinkedList
{
public:
    SinglyLinkedListNode *head;
    SinglyLinkedListNode *tail;

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

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

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

        this->tail = node;
    }
};

void print_singly_linked_list(SinglyLinkedListNode *node, string sep)
{
    while (node)
    {
        cout << node->data;

        node = node->next;

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

void free_singly_linked_list(SinglyLinkedListNode *node)
{
    while (node)
    {
        SinglyLinkedListNode *temp = node;
        node = node->next;

        free(temp);
    }
}
bool compare_lists(SinglyLinkedListNode *head1, SinglyLinkedListNode *head2)
{
    if (head1 == NULL && head2 == NULL)
        return true;
    if (head1 != NULL && head2 != NULL)
    {
        if (head1->data == head2->data)
            return compare_lists(head1->next, head2->next);
        else
            return false;
    }
    else
        return false;
}

int main()
{

    SinglyLinkedList *llist1 = new SinglyLinkedList();

    int llist1_count = 3;
    llist1->insert_node(1);
    llist1->insert_node(2);
    llist1->insert_node(3);

    SinglyLinkedList *llist2 = new SinglyLinkedList();

    int llist2_count = 4;
    llist2->insert_node(1);
    llist2->insert_node(2);
    llist2->insert_node(3);
    llist2->insert_node(4);

    bool result = compare_lists(llist1->head, llist2->head);

    cout << result << "\n";

    return 0;
}