#include <iostream>
#include <pthread.h>
#include <string>
using namespace std;

struct element {
    int info;
    element* next;
    element* prev;
};

struct dynamic_list {
    element* head;
    element* tail;
};

void addElement(dynamic_list& list, int part);
void deleteElement(dynamic_list& list, int number, short mode);
bool checkEmpty(dynamic_list list);
void showList(dynamic_list list);
void findElement(dynamic_list& list, int elem);

int main()
{
    int part;
    int number;
    int elem;
    dynamic_list list;
    list.head = NULL;
    list.tail = list.head;

    for (int i =0; i < 10; i++)
    {
        cin >> part;
        addElement(list, part);
    }
    showList(list);

    int choice;
    cout << "choice";
    cin >> choice;
    while (choice != 5) {

        switch (choice) {
            case 1: //Âñòàâêà ýëåìåíòà
                cout << "Ââåäèòå ÷èñëî:\n";
                cin >> part;
                //cout << "\nÊóäà ñëåäóåò âñòàâèòü íîâûé ýëåìåíò? (1 - âî ãëàâó ñïèñêà, 2 - â õâîñò ñïèñêà, 3 - ïåðåä óêàçàííûì, 4 - çà óêàçàííûì)\n";
                //cin >> mode;
                //if (mode == 3 || mode == 4) {
                //  cout << "Óêàæèòå íîìåð ýëåìåíòà:\n";
                //  cin >> number;
                //}
                addElement(list, part);
                //cout << MENU;
                cin >> choice;
                break;
            case 2: //Óäàëåíèå ýëåìåíòà
                cout << "Êàêîé ýëåìåíò ñëåäóåò óäàëèòü? (1 - ñ ãîëîâû, 2 - ñ õâîñòà, 3 - óêàçàííûé)\n";
                short mode;
                cin >> mode;
                if (mode == 3) {
                    cout << "Óêàæèòå íîìåð ýëåìåíòà:\n";
                    cin >> number;
                }
                deleteElement(list, number, mode);
                //cout << MENU;
                cin >> choice;
                break;
            case 3: //Ïîêàçàòü ñïèñîê
                showList(list);
                //cout << MENU;
                cin >> choice;
                break;
            case 4:
                cin >> elem;
                findElement(list, elem);
                cin >> choice;
                break;

            case 5: //Âûõîä
                break;
            default:
                cout << "\aÒðåáóåòñÿ ââåñòè ÷èñëî îò 1 äî 4.\n";
                //cout << MENU;
                cin >> choice;
                break;
        }
    }


    return 0;
}

void addElement(dynamic_list& list, int part)
{
    element* newElement = new element;
    element* current;
    newElement->info = part;
    newElement->next = NULL;
    newElement->prev = NULL;
    if (checkEmpty(list)) {
        list.head = newElement;
        list.tail = newElement;

    }
    list.tail->next = newElement;
    newElement->prev = list.tail;
    list.tail = newElement;
    list.tail->next = NULL;

}

void deleteElement(dynamic_list& list, int number, short mode)
{
    switch (mode) {
        case 1: //Óäàëåíèå ýëåìåíòà ñ ãîëîâû
            if (list.tail == list.head) {
                list.head = NULL;
                list.tail = NULL;
                cout << "Óäàëåíèå ýëåìåíòà ïðîøëî óñïåøíî.\n";
                break;
            }
            list.head = list.head->next;
                list.head->prev = NULL;
            cout << "Óäàëåíèå ýëåìåíòà ïðîøëî óñïåøíî.\n";
            break;
        case 2: //Óäàëåíèå ýëåìåíòà ñ õâîñòà
            if (list.tail == list.head) {
                list.head = NULL;
                list.tail = NULL;
                cout << "Óäàëåíèå ýëåìåíòà ïðîøëî óñïåøíî.\n";
                break;
            }
            list.tail = list.tail->prev;
            list.tail->next = NULL;
            cout << "Óäàëåíèå ýëåìåíòà ïðîøëî óñïåøíî.\n";
            break;
        case 3: //Óäàëåíèå óêàçàííîãî ýëåìåíòà
            element* current;
            current = list.head;
            if (number == 1) {
                deleteElement(list, 1, 1);
                break;
            }
            int i = 1;
            for (; i < number && current != NULL; i++)
                current = current->next;
            if (current == list.tail) {
                deleteElement(list, i, 2);
                break;
            }
            if (current != NULL) {
                current->prev->next = current->next;
                current->next->prev = current->prev;
                delete current;
                cout << "\nÓäàëåíèå ýëåìåíòà ïðîøëî óñïåøíî.\n";
                break;
            }
            else {
                cout << "\nÝëåìåíò ñ òàêèì íîìåðîì íå ñóùåñòâóåò.\n";
                return;
            }
    }
}

bool checkEmpty(dynamic_list list)
{
    return (list.head == NULL || list.tail == NULL) ? true : false;
}

void showList(dynamic_list list)
{
    cout << "Òåêóùèé ñïèñîê:\n";
    while (list.head != NULL) {
        cout << list.head->info << ' ';
        list.head = list.head->next;
    }
    cout << '\n';
}

void findElement(dynamic_list& list, int elem)
{
    element * k = new element;
    while (list.head != NULL) {
        k->info = list.head->info;
        if (k->info == elem){
            cout << elem;
            break;
        }
        else
            list.head = list.head->next;
    }
}