#include <stdio.h>
#include <stdlib.h>
#include <string.h>

typedef struct Node {
    char *content;
    struct Node *yes;
    struct Node *no;
} Node;

Node* create_node(const char *content) {
    Node *new_node = (Node*)malloc(sizeof(Node));
    new_node->content = strdup(content);
    new_node->yes = NULL;
    new_node->no = NULL;
    return new_node;
}

void free_tree(Node *root) {
    if (root) {
        free(root->content);
        free_tree(root->yes);
        free_tree(root->no);
        free(root);
    }
}

int count_answers(Node *root) {
    if (!root) return 0;
    if (root->yes == NULL && root->no == NULL) return 1; // It's an answer
    return count_answers(root->yes) + count_answers(root->no);
}

Node* parse_rules() {
    char line[256];
    Node *root = NULL, *current = NULL;
    Node *stack[100];
    int stack_top = -1;

    while (fgets(line, sizeof(line), stdin)) {
        // Trim newline and spaces
        line[strcspn(line, "\n")] = 0;
        if (strlen(line) == 0) break; // End of rules

        if (line[0] == '*') { // This is an answer
            Node *answer = create_node(line + 1);
            if (stack_top >= 0) {
                if (stack[stack_top]->yes == NULL)
                    stack[stack_top]->yes = answer;
                else
                    stack[stack_top]->no = answer;
            }
        } else { // This is a question
            Node *question = create_node(line);
            if (stack_top >= 0) {
                if (stack[stack_top]->yes == NULL)
                    stack[stack_top]->yes = question;
                else
                    stack[stack_top]->no = question;
            }
            stack[++stack_top] = question;
        }
    }

    if (stack_top >= 0) {
        root = stack[0];
    }

    return root;
}

void ask_question(Node *node) {
    if (!node) return;
    if (node->yes == NULL && node->no == NULL) {
        printf("Koniec\n");
        return;
    }

    // Print the current question
    printf("%s?\n", node->content);
    if (node->yes) {
        printf("* %s\n", node->yes->content);
    }
    if (node->no) {
        printf("* %s\n", node->no->content);
    }

    // Prompt for input
    printf("\n");
    printf("n\n");

    char response;
    while (1) {
        response = getchar();
        getchar(); // To capture newline
        if (response == 'a') {
            ask_question(node->yes);
            break;
        } else if (response == 'n') {
            ask_question(node->no);
            break;
        } else {
            printf("Neplatna odpoved, koniec.\n");
            break;
        }
    }
}

int main() {
    // General system information only once
    printf("Expert z bufetu to vie.\n");

    Node *root = parse_rules();
    if (!root) {
        printf("Chybne pravidla.\n");
        return 1;
    }

    int answer_count = count_answers(root);
    printf("Pozna %d druhov ovocia a zeleniny.\n", answer_count);

    // Ask the first question
    printf("Odpovedajte 'a' pre prvu moznost alebo 'n' pre druhu moznost.\n");
    ask_question(root);
    free_tree(root);

    return 0;
}