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

#define SIZE 256

typedef struct tree {
    char value[SIZE];
    struct tree *left;
    struct tree *right;
} Tree;

void strip_newline(char *s) {
    int len = strlen(s);
    if (len > 0 && s[len-1] == '\n') {
    	s[len-1] = '\0';
    }
}


// rekurzivne nacitanie stromu v preorder
Tree* read_tree() {
    char buffer[SIZE];

    if (!fgets(buffer, SIZE, stdin))
        return NULL;

    // prazdny riadok -> koniec
    if (strcmp(buffer, "\n") == 0)
        return NULL;

    Tree *node = calloc(1, sizeof(Tree));
    strcpy(node->value, buffer);

    // odpoved -> list
    if (buffer[0] == '*') {
        node->left = NULL;
	node->right = NULL;
    } else {
	node->left = read_tree();
	node->right = read_tree();
    }
    return node;
}

void destroy_tree(Tree *tree) {
    if (!tree) return;
    destroy_tree(tree->left);
    destroy_tree(tree->right);
    free(tree);
}
 
int count_leaves(Tree *tree) {
    if (!tree) return 0;
    if (!tree->left && !tree->right) return 1;
    return count_leaves(tree->left) + count_leaves(tree->right);
}

// spustenie znalostneho systemu
int run_system(Tree *node) {
    if (node == NULL){ 
	return 1;
    }

    if (node->value[0] == '*'){
    	printf("%s\n", node->value);
	return 1;
    }

    char c[10];
    printf("%s\n", node->value);
    while (1) {
    	if (fgets(c, sizeof(c), stdin) == NULL) {
    		printf("Koniec vstupu\n");
		return 0;
    	}
    	strip_newline(c);

    	if (strlen(c) != 0) break;
    }

    if (!node->left && !node->right) {
	printf("Koniec vstupu\n");
        return 0;
    }

    if (strcmp(c,"a") == 0) {
	if (node->left != NULL){
        	return run_system(node->left);
	}
    } else if (strcmp(c, "n") == 0) {
	if (node->right != NULL){
        	return run_system(node->right);
	}
    } else {
        printf("Nerozumiem\n");
	return 0;
    }
    return 1;
}

int main() {
    Tree *root = read_tree();
    printf("Expert z bufetu to vie.\n");
    
    if (root == NULL){
    	printf("Chybna databaza\n");
	return 0;
    }

    /* // skontrolovat prazdny riadok
    char buffer[SIZE];
    if (!fgets(buffer, SIZE, stdin) || strlen(buffer) > 1) {
        printf("Chybna databaza\n");
        destroy_tree(root);
        return 0;
    }*/

    int leaves = count_leaves(root);

    printf("Pozna %d druhov ovocia a zeleniny.\n", leaves);
    printf("Odpovedajte 'a' pre prvu moznost alebo 'n' pre druhu moznost.\n");
    int continueworking = run_system(root);
    if (continueworking){
    	printf("Koniec\n");
    }
    destroy_tree(root);
    return 0;
}