tema2

#include <iostream>
#include <memory>
#include <string>

template<typename T>
struct Node
{
    T value;
    std::shared_ptr<Node<T>> prev, next;
};

template <typename T>
class dllist
{
public:
    dllist();

    void push_back(T value);

    T operator[](size_t index);

    size_t size() const;
private:
    size_t _size = 0;

    std::shared_ptr<Node<T>> _first, _last;
};

template <typename T>
dllist<T>::dllist()
{

}

template <typename T>
void dllist<T>::push_back(T value)
{
    if (_size == 0)
    {
        _first = _last = std::make_shared<Node<T>>();
        _first->value = value;
    }
    else
    {
        _last->next = std::make_shared<Node<T>>();
        _last->next->prev = _last;
        _last = _last->next;
        _last->value = value;
    }
    _size++;
}

template <typename T>
T dllist<T>::operator[](const size_t index)
{
    if (index >= _size || index < 0)
        throw std::out_of_range("List index out of range.");

    std::shared_ptr<Node<T>> p;

    if (index < _size / 2)
    {
        p = _first;
        for (size_t i = 0; i < index; i++)
        {
            p = p->next;
        }
    }
    else
    {
        p = _last;
        for (int64_t i = _size - 1; i > index; i--)
        {
            p = p->prev;
        }
    }

    return p->value;
}

template <typename T>
size_t dllist<T>::size() const
{
    return _size;
}

int main()
{
    try
    {
        dllist<char> word;

        std::string str;
        std::cin >> str;
        for (auto c : str)
        {
            word.push_back(c);
        }

        bool bEPalindrom = true;
        for (size_t i = 0; i < word.size() / 2; i++)
        {
            if (word[i] != word[word.size() - 1- i])
            {
                bEPalindrom = false;
                break;
            }
        }

        if (bEPalindrom)
            std::cout << "E palindrom." << std::endl;
        else
            std::cout << "Nu e palindrom." << std::endl;
    }
    catch (std::exception& e)
    {
        std::cout << e.what() << std::endl;
    }

    std::cout << "Press any key to quit...";
    std::getchar(); std::getchar();
}