#include <iostream>
using namespace std;

//создаем звено
typedef struct Node{
    void *value;
    struct Node *next;
    struct Node *prev;
} Node;
//создаем двусвязный список
typedef struct DblLinkedList{
    size_t size;
    Node *head;
    Node *tail;
};
//добавление в конец
void pushBack(DblLinkedList *list, void *data){
    Node *tmp = (Node*)malloc(sizeof(Node));
    if (tmp == NULL){
        exit(3);
    }
    tmp->value = data;
    tmp->next = NULL;
    tmp->prev = list->tail;
    if (list->tail){
        list->tail->next = tmp;
    }
    list->tail = tmp;
    if (list->head == NULL){
        list->head = tmp;
    }
    list->size++;
}
//создаем экземпляр структуры
DblLinkedList* createDblLinkedList(){
    DblLinkedList *tmp = (DblLinkedList*)malloc(sizeof(DblLinkedList));
    tmp->size = 0;
    tmp->head = tmp->tail = NULL;
    return tmp;
}
//удаляем структуру
void DeleteDblLinkedList(DblLinkedList **list){
    Node *tmp = (*list)->head;
    Node *next = NULL;
    while (tmp){
        next = tmp->next;
        free(tmp);
        tmp = next;
    }
    free(*list);
    (*list) = NULL;
}
//получение н-ого ??
Node* getNthq (DblLinkedList *list, size_t index){
    Node *tmp = NULL;
    size_t i;
    if (index < list->size / 2){
        i = 0;
        tmp = list->head;
        while(tmp && i < index){
            tmp = tmp ->next;
            i++;
        }
    } else {
        i = list->size - 1;
        tmp = list ->tail;
        while(tmp && i > index){
            tmp = tmp->prev;
            i--;
        }
    }
    return tmp;
}
//удаление из н-ого места
void* deleteNth(DblLinkedList *list, size_t index){
    Node *elm = NULL;
    void *tmp = NULL;
    elm = getNthq(list, index);
    if (elm == NULL){
        exit(1);
    }
    if (elm->prev){
        elm->prev->next = elm->next;
    }
    if (elm->next){
        elm->next->prev = elm->prev;
    }
    if (!elm->prev){
        list->head = elm->next;
    }
    if (!elm->next){
        list->tail = elm->prev;
    }
    free(elm);
    list->size--;
    return tmp;
}
// Удаление введеного с клавиатуры
Node* getNth(DblLinkedList *list, void* n) {
    Node *tmp = list->head;
    size_t i = 0;
    while (tmp) {
        if (*((float*)tmp->value) != *((float*)(n))){
            tmp = tmp->next;
            i++;
        } else {
            Node *tmp2 = tmp->next;
            deleteNth(list, i);
            if (!tmp2){
                break;
            }
            tmp = tmp2->next;
            i++;
            //break;
        }
    }
    return tmp;
}

//печать
void printDblLinkedList(DblLinkedList *list, void (*fun)(void*)) {
    Node *tmp = list->head;
    while (tmp){
        fun(tmp->value);
        tmp = tmp->next;
    }
    cout<<endl;
}
void printFloat (void *value){
    cout<<*(float*) value<<" ";
}
//создание списка из массива
DblLinkedList* fromArray(void *arr, size_t n, size_t size) {
    DblLinkedList *tmp = NULL;
    size_t i = 0;
    if (arr == NULL){
        exit(2);
    }
    tmp = createDblLinkedList();
    while (i < n){
        pushBack(tmp, ((char*)arr+i*size));
        return tmp;
    }
}

int main() {
    DblLinkedList *list = createDblLinkedList();
    float a, b, c, d, e, f,g;

    a = 10;
    b = 20;
    c = 30;
    d = 40;
    e = 50;
    f = 60;
    g = 0;
    pushBack(list, &a);
    pushBack(list, &b);
    pushBack(list, &c);
    pushBack(list, &d);
    pushBack(list, &e);
    pushBack(list, &f);
    printDblLinkedList(list, printFloat);
    cout<<"Vvedi chislo: ";
    cin>>g;
    getNth(list, &g);
    printDblLinkedList(list, printFloat);
    cout<<"length "<<list->size<<endl;
    cout<<"head  "<<*((float*)(list->head->value))<<endl;
    cout<<"tail "<<*((float*)(list->tail->value))<<endl;
    DeleteDblLinkedList(&list);
    /*char c;
    float a;
    for (;;) {
        cout << "Vvesti element? (y/n) ";
        cin>>c;
        if (c == 'n') break;
        cout << "Vvedite chislo tipa float: ";
        cin >> a;
        pushBack(list, &a);
    } */




    return 0;

}






















    /*float a, b, c, d, e, f, g, h;

    a = 10.3;
    b = 20.9;
    c = 30.5;
    d = 40.6;
    e = 50.7;
    f = 60.8;
    g = 70.9;
    h = 80.4;
    pushBack(list, &d);
    pushBack(list, &e);
    pushBack(list, &f);
    printDblLinkedList(list, printFloat);
    cout<<"length "<<list->size<<endl;
    cout<<"nth 2 "<<*((float*)(getNthq(list, 2))->value)<<endl;
    cout<<"nth 5 "<<*((float*)(getNthq(list, 5))->value)<<endl;
    cout<<"head "<<*((float*)(list->head->value))<<endl;
    cout<<"tail "<<*((float*)(list->tail->value))<<endl;
    cout<<"legth "<<list->size<<endl;
    printDblLinkedList(list, printFloat);
    printDblLinkedList(list, printFloat);
    deleteNth(list, 0);
    printDblLinkedList(list, printFloat);
    DeleteDblLinkedList(&list); */