Print in reverse.cpp

#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);
    }
}
/*
 * Complete the 'reversePrint' function below.
 *
 * The function accepts INTEGER_SINGLY_LINKED_LIST llist as parameter.
 */

/*
 * For your reference:
 *
 * SinglyLinkedListNode {
 *     int data;
 *     SinglyLinkedListNode* next;
 * };
 *
 */

void reversePrint(SinglyLinkedListNode* llist) {
   vector<int> arr;
    int len = 0;
    if(llist == NULL){
        return;
    }
    else{
        SinglyLinkedListNode* temp = llist;
        while(temp != NULL){
            arr.push_back(temp->data);
            len += 1;
            temp = temp -> next;
        }
        for(int i=len-1; i>=0; i--){
            cout<<arr[i]<<endl;
        }
    }
}
int main()
{
    int tests;
    cin >> tests;
    cin.ignore(numeric_limits<streamsize>::max(), '\n');

    for (int tests_itr = 0; tests_itr < tests; tests_itr++) {
        SinglyLinkedList* llist = new SinglyLinkedList();

        int llist_count;
        cin >> llist_count;
        cin.ignore(numeric_limits<streamsize>::max(), '\n');

        for (int i = 0; i < llist_count; i++) {
            int llist_item;
            cin >> llist_item;
            cin.ignore(numeric_limits<streamsize>::max(), '\n');

            llist->insert_node(llist_item);
        }

        reversePrint(llist->head);
    }

    return 0;
}