PismenZad2

#include <iostream>
#include <stack>

using namespace std;

struct Node
{
    int data;
    Node* next;
};


void RemoveSingles(Node*& head);
void Push(Node*& head, int data);
void Append(Node*& head, int data);
void printList(Node* head);
void DeleteList(Node*& head);

int main()
{
    Node* llist = nullptr;
    int n;
    cout << "Enter number of elements: ";
    cin >> n;
    cout << "Enter list elements: ";
    for (int i = 0; i < n; i++)
    {
        int num;
        cin >> num;
        Append(llist, num);
    }
    RemoveSingles(llist);
    cout << endl;
    printList(llist);
    return 0;
}

void RemoveSingles(Node*& head)
{
    if (head == nullptr)
    {
        return;
    }
    stack<int> elements;
    Node* current = head;
    while (current != nullptr)
    {
        int num = current->data;
        elements.push(num);
        current = current->next;
        cout << "Push: " << num << endl;
        bool flag = false;
        while (current != nullptr && current->data == num)
        {
            flag = true;
            elements.push(current->data);
            cout << "Push: " << current->data << endl;
            current=current->next;
        }
        if (!flag)
        {
            cout << "Pop: " << elements.top() << endl;
            elements.pop(); // remove single element
        }
    }
    DeleteList(head);
    while (!elements.empty())
    {
        Push(head, elements.top());
        elements.pop();
    }
}

void Push(Node*& head, int data)
{
    Node* n = new Node();
    n->data = data;
    n->next = head;
    head = n;
}

void Append(Node*& head, int data)
{
    Node* n = new Node();
    n->data = data;
    if (head == nullptr)
    {
        n->next = head;
        head = n;
    }
    else
    {
        Node* current = head;
        while(current->next != nullptr)
        {
             current = current->next;
        }
        n->next = current->next;
        current->next = n;
    }
}

void printList(Node* head)
{
    if (head == nullptr)
    {
        cout << "Empty list" << endl;
    }
    Node* current = head;
    while (current != nullptr)
    {
        cout << current->data << " ";
        current = current->next;
    }
    cout << endl;
}

void DeleteList(Node*& head)
{
    Node* current = head;
    Node* todelete;
    while (current != nullptr)
    {
        todelete = current;
        current = current->next;
        delete todelete;
    }
    head = nullptr;
}