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

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


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


Node* load_tree(int *item_count) {
    char line[100];
    if (!fgets(line, sizeof(line), stdin) || line[0] == '\n') {
        return NULL;
    }

    line[strcspn(line, "\n")] = 0;  

    if (line[0] == '*') {
        (*item_count)++;
        return create_node(line + 1);  
    } else {
        Node *node = create_node(line);  
        node->yes = load_tree(item_count);
        node->no = load_tree(item_count);
        return node;
    }
}


void free_tree(Node *node) {
    if (node) {
        free(node->text);
        free_tree(node->yes);
        free_tree(node->no);
        free(node);
    }
}


void run_system(Node *node) {
    while (node) {
        if (node->yes == NULL && node->no == NULL) {
            printf("Expert z bufetu to vie.\n");
            printf("* %s\n", node->text);
            printf("Koniec\n");
            break;
        }
        
        printf("%s\n", node->text);
        char answer;
        scanf(" %c", &answer);

        if (answer == 'a') {
            node = node->yes;
        } else if (answer == 'n') {
            node = node->no;
        } else {
            printf("Odpovedajte 'a' pre prvu moznost alebo 'n' pre druhu moznost.\n");
            break;
        }
    }
}

int main() {
    int item_count = 0;
    printf("Načítajte bázu znalostí:\n");
    Node *root = load_tree(&item_count);

    if (root == NULL) {
        printf("Chba: bázu znalostí sa nepodarilo načítať.\n");
        return 1;
    }

    printf("Pozna %d druhov ovocia a zeleniny.\n", item_count);
    printf("Odpovedajte 'a' pre prvu moznost alebo 'n' pre druhu moznost.\n");
    run_system(root);
    
    free_tree(root);
    return 0;
}