#include <iostream>

using namespace std;

struct node
{
    int val;
    node *next, *prev;
};

void del(node*& head, node*& tail, node*& p, int &count)
{
    if (p->prev)
        p->prev->next = p->next;
    else
        head = p->next;
    if (p->next)
        p->next->prev = p->prev;
    else
        tail = p->prev;
    delete p;
    count--;
}

void ins_tail(node*& head, node*&tail, int x, int &count)
{
    node* nowy = new node;
    nowy->next = NULL;
    nowy->prev = NULL;
    nowy->val = x;
    if (!head)
    {
        head = nowy;
        tail = nowy;
    }
    else
    {
        nowy->prev = tail;
        tail->next = nowy;
        tail = nowy;
    }count++;
}

void ins_head(node*& head, node*& tail, int x, int &count)
{
    node* nowy = new node;
    nowy->next = NULL;
    nowy->prev = NULL;
    nowy->val = x;
    if (!head)
    {
        head = nowy;
        tail = nowy;
    }
    else
    {
        nowy->next = head;
        head->prev = nowy;
        head = nowy;
    }count++;
}

void ins_after(node*& p, int x, int &count)
{
    node* nowy = new node;
    nowy->val = x;
    nowy->next = p->next;
    nowy->prev = p;
    p->next->prev = nowy;
    p->next = nowy;
    count++;
}

void ins_before(node*& p, int x, int &count)
{
    node* nowy = new node;
    nowy->val = x;
    nowy->next = p;
    nowy->prev = p->prev;
    p->prev->next = nowy;
    p->prev = nowy;
    count++;
}

void show(node* head)
{
    while (head)
    {
        cout << head->val << " ";
        head = head->next;
    }cout << endl;
}

int main()
{
    node* head = NULL;
    node* tail = NULL;
    int wybor=0, liczba=0, numer=0, count=0;
    node* p = NULL;
    do
    {
        p = head;
        system("CLS");
        cout << "Elementy listy: " << endl;
        show(head);
        cout << "Ilosc elementow w liscie: " << count << endl;
        cout << "Menu listy: " << endl << "1. Dodaj na poczatek" << endl << "2. Dodaj na koniec" << endl << "3. Dodaj po danym elemencie" << endl << "4. Dodaj przed danym elementem" << endl << "5. Usun dowolny element" << endl << "Wybor: ";
        cin >> wybor;

        switch (wybor)
        {
        case 1:
            cout << "Podaj liczbe: ";
            cin >> liczba;
            ins_head(head, tail, liczba, count);
            break;

        case 2:
            cout << "Podaj liczbe: ";
            cin >> liczba;
            ins_tail(head, tail, liczba, count);
            break;

        case 3:
            cout << "Podaj numer elementu: ";
            cin >> numer;
            cout << "Podaj liczbe: ";
            cin >> liczba;
            for (int i = 1; i < numer; i++)
                p = p->next;
            ins_after(p, liczba, count);
            break;

        case 4:
            cout << "Podaj numer elementu: ";
            cin >> numer;
            cout << "Podaj liczbe: ";
            cin >> liczba;
            for (int i = 1; i < numer; i++)
                p = p->next;
            ins_before(p, liczba, count);
            break;

        case 5:
            cout << "Podaj numer elementu: ";
            cin >> numer;
            for (int i = 1; i < numer; i++)
                p = p->next;
            del(head, tail, p, count);
            break;
        }
    } while (wybor != 10);

    return 0;
}