// ConsoleApplication1.cpp: определяет точку входа для консольного приложения.
//

#include "stdafx.h"
#include <stdlib.h>

typedef struct item {
    int value;
    item* next;
} item;

typedef struct item_2 {
    int value;
    item_2* next;
    item_2* prev;
} item_2;

/*typedef struct queue {
    item* list;
} queue;

void add_in_q(queue* q, int value) {
    add_in_tail(q->list, value);
}

int remove_from_q(queue* q) {
    int temp = get_tail(q->list);
    remove_head(q->list);
    return temp;
}*/

item* add_in_head(item* head, int new_value) {
    item* new_item = (item*)malloc(sizeof(item));
    new_item->value = new_value;
    new_item->next = head;
    return new_item;
}

item* add_in_tail(item* head, int new_value) {
    item* new_item = (item*)malloc(sizeof(item));
    new_item->value = new_value;
    new_item->next = NULL;
    if (!head)
        return new_item;

    item* current = head;
    while (current->next) {
        current = current->next;
    }
    current->next = new_item;
    return head;
}

item* remove_head(item* head) {
    if (!head)
        return NULL;
    item* temp = head;
    head = head->next;
    free(temp);
    return head;
}

item* remove_tail(item* head) {
    if (!head)
        return NULL;
    if (!head->next) {
        free(head);
        return NULL;
    }
    item* current = head;
    while (current->next->next) {
        current = current->next;
    }
    free(current->next);
    current->next = NULL;
    return head;
}

void print_list(item* head) {
    item* current = head;
    while (current) {
        printf("%4d", current->value);
        current = current->next;
    }
    printf("\n");
    return;
}

void reverse_print(item* head) {
    if (head->next)
        reverse_print(head->next);
    printf("%4d", head->value);
    return;
}

item* remove_by_value(item* head, int value) {
    if (!head)
        return NULL;
    if (head->value == value) {
        return remove_head(head);
    }
    item* current = head;
    while (current->next && current->next->value != value) {
        current = current->next;
    }
    if (!current->next)
        return head;
    item* temp = current->next;
    current->next = current->next->next;
    free(temp);
    return head;
}

item* clear_list(item* head) {
    item* current = head;
    item* temp;
    unsigned len;
    unsigned j;
    // get_len();
    while (j < len) {//(current) {
        /*temp = current;
        current = current->next;
        free(temp);*/
        current = remove_head(current);
        j++;
    }
    return NULL;
}

int main()
{
    item* head = NULL;
    head = add_in_head(head, 0);
    head = add_in_head(head, 2);
    head = add_in_head(head, 4);
    head = add_in_head(head, 6);
    head = add_in_tail(head, 3);
    head = add_in_tail(head, 3);
    head = add_in_tail(head, 8);
    head = add_in_tail(head, 3);
    head = add_in_tail(head, 8);
    print_list(head);
    head = remove_by_value(head, 8);
    print_list(head);

    reverse_print(head);
    head = clear_list(head);
    print_list(head);
    getchar();
    return 0;
}