linkedNodeListAdvanced

#include "pch.h"
#include <iostream>
#include <functional>

using namespace std;

struct Node
{
    int value = 0;
    Node * prev = nullptr;
    Node * next = nullptr;
};

struct NodeList
{
    Node* head = nullptr;
    Node* tail = nullptr;
    Node* curr = nullptr;

    void add(int val)
    {
        if (!head)
        {
            head = new Node{ val };
            tail = head;
            return;
        }
        if (!tail->next)
        {
            tail->next = new Node{ val, tail };
            tail = tail->next;
            return;
        }
    };
    void show()
    {
        Node* ptr = head;
        if (!ptr) std::cout << "Empty NodeList!" << std::endl;
        while (ptr)
        {
            std::cout << ptr->value << std::endl;
            ptr = ptr->next;
        }
    }

    void showReverse()
    {
        Node* ptr = tail;
        if (!ptr) std::cout << "Empty NodeList!" << std::endl;
        while (ptr)
        {
            std::cout << ptr->value << std::endl;
            ptr = ptr->prev;
        }
    }
    void deleteLast()
    {
        Node* ptr = nullptr;
        if (!tail) std::cout << "Empty NodeList!" << std::endl;
        ptr = tail;
        tail = tail->prev;
        tail->next = nullptr;
        std::cout << "Deleting.. " << ptr->value;
        delete ptr;
        std::cout << " Done!" << std::endl;
    }

    void deleteAll()
    {
        Node* ptr = nullptr;
        if (!tail) std::cout << "Empty NodeList!" << std::endl;
        while (tail)
        {
            ptr = tail;
            tail = tail->prev;
            std::cout << "Deleting.. " << ptr->value;
            delete ptr;
            std::cout << " Done!" << std::endl;
        }
        head = nullptr;
        tail = nullptr;

    }

    void forEach(std::function <void(int&)> funct)
    {
        Node* ptr = head;
        if (!ptr) std::cout << "Empty NodeList!" << std::endl;
        while (ptr)
        {
            funct(ptr->value);
            ptr = ptr->next;
        }
    }

    void forEachReverse(std::function <void(int&)> funct)
    {
        Node* ptr = tail;
        if (!ptr) std::cout << "Empty NodeList!" << std::endl;
        while (ptr)
        {
            funct(ptr->value);
            ptr = ptr->prev;
        }
    }

    int count()
    {
        Node* ptr = head;
        if (!ptr) return 0;
        int cnt = 0;
        while (ptr)
        {
            cnt++;
            ptr = ptr->next;
        }
        return cnt;
    }

    void begin()
    {
        curr = head;
    }

    void end()
    {
        curr = tail;
    }

    Node* get()
    {
        return curr;
    }

    Node* getNext()
    {
        curr = curr->next;
        return curr;
    }

    Node* getPrev()
    {
        curr = curr->prev;
        return curr;
    }
};

int main()
{
    NodeList* list = new NodeList;
    list->show();
    list->add(2902);
    list->add(2407);
    list->add(2802);
    list->add(2607);
    list->show();
    std::cout << "####" << std::endl;
    list->showReverse();
    list->deleteAll();
    list->showReverse();
    list->add(29022);
    list->add(24073);
    list->add(28024);
    list->add(26075);
    list->show();
    std::cout << "####" << std::endl;
    list->deleteLast();
    list->forEach([](int& arg) {arg = arg + 1; });
    list->forEachReverse([](int& arg) {std::cout << arg << std::endl; });
    std::cout << "There are: " << list->count() << " nodes" << std::endl;
    list->begin();
    for (int i = 0; i < list->count(); i++)
    {
        std::cout << "Iteration " << i << " " << list->get()->value << std::endl;
        list->getNext();
    }
    std::cout << "####" << std::endl;
    list->end();
    for (int i = 0; i < list->count(); i++)
    {
        std::cout << "Iteration " << i << " " << list->get()->value << std::endl;
        list->getPrev();
    }
    list->deleteAll();
    list->show();
}