#define _CRT_SECURE_NO_WARNINGS
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

typedef struct Node {
    char *data;
    struct Node* next;
} Node;

Node *add_first(Node *a, char* data)
{
    Node *c = (Node*)malloc(1 * sizeof(Node));
    *c = { data, a };
    return c;
}

Node *reverse(Node* a)
{
    Node *b = a, *c = (Node*)malloc(1 * sizeof(Node));
    *c = { a->data, NULL };
    while (b->next != NULL)
    {
        b = b->next;
        c = add_first(c, b->data);
    }
    return c;
}

Node *add_kvadrat(Node *a, char* data)
{
    Node *c = (Node*)malloc(1 * sizeof(Node));
    *c = { data, a };
    if (c->next)
        c->next = reverse(c->next);
    c = reverse(c);
    return c;
}

void print_Node(Node *a)
{
    if (strlen(a->data))
        printf("%s ", a->data);
    if (a->next)
        print_Node(a->next);
    else
        printf("\n");
}

Node *init(char* b) {
    Node *a = (Node*)malloc(sizeof(Node));
    a->data = b;
    a->next = NULL;
    return(a);
}

Node* getLast(Node *head) {
    if (head == NULL) {
        return NULL;
    }
    while (head->next) {
        head = head->next;
    }
    return head;
}

void add(Node *head, char* value) {
    Node *last = getLast(head);
    Node *tmp = (Node*)malloc(sizeof(Node));
    tmp->data = value;
    tmp->next = NULL;
    last->next = tmp;
}

void seminar_list() {
    FILE* f1 = freopen("in.txt", "r", stdin);
    FILE* f2 = freopen("out.txt", "w", stdout);
    Node *head;
    head = init("A");
    add(head, "B");
    add(head, "C");
    add(head, "D");
    print_Node(head);
    head = reverse(head);
    print_Node(head);
    fclose(f1);
    fclose(f2);
}

int main(){
    seminar_list();
}