1. Explain the algorithm ideas behind the insertNode, deleteNode, and appendNode functions?

2. Explain the primary purpose of the following functions?

// Function 1
int NumberList::mysteryFunction1(ListNode *nodePtr) const
{
    if (nodePtr != nullptr)
        return 1 + mysteryFunction1(nodePtr->next);
    else
        return 0;
}

// Function 2
void NumberList::mysteryFunction2(ListNode *nodePtr) const
{
    if (nodePtr != nullptr)
    {
        mysteryFunction3(nodePtr->next);
        cout << nodePtr->value << " ";
    }
}

// Function 3
void NumberList::mysteryFunction3() {
    ListNode *curr = head;
    ListNode *prev = nullptr;
    ListNode *next = nullptr;

    while (curr != nullptr) {
        next = curr->next;
        curr->next = prev;
        prev = curr;
        curr = next;
    }
    head = prev;
}

3. Integrate these functions into the project and run a demo