usaa24/cv7/program.c

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

#define SIZE 256

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

struct tree* read_tree()
{
    char buffer[SIZE];
    if (!fgets(buffer, SIZE, stdin) || buffer[0] == '\n')
    {
        return NULL;
    }

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

    struct tree *node = (struct tree*)malloc(sizeof(struct tree));
    assert(node != NULL);
    strcpy(node->value, buffer);

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

    return node;
};

void free_tree(struct tree *tree)
{
    if (tree == NULL)
    {
        return;
    }
    free_tree(tree->left);
    free_tree(tree->right);
    free(tree);
}

int count_leaf_nodes(struct tree *node)
{
    if (node == NULL)
    {
        return 0;
    }
    if (node->left == NULL && node->right == NULL)
    {
        return 1;
    }
    return count_leaf_nodes(node->left) + count_leaf_nodes(node->right);
}

int count_non_leaf_nodes(struct tree *node)
{
    if (node == NULL || (node->left == NULL && node->right == NULL))
    {
        return 0;
    }
    return 1 + count_non_leaf_nodes(node->left) + count_non_leaf_nodes(node->right);
}

void interact(struct tree *node)
{
    if (node == NULL)
    {
        return;
    }

    printf("%s (a/n) ?\n", node->value);

    if (node->left == NULL && node->right == NULL)
    {
        printf("Koniec\n");
        return;
    }

    char answer;
    while (scanf(" %c", &answer) == 1)
    {
        if (answer == 'a')
        {
            interact(node->left);
            return;
        }
        else if (answer == 'n')
        {
            interact(node->right);
            return;
        }
        else
        {
            printf("Odpovedajte 'a' alebo 'n'\n");
        }
    }
}

int main()
{
    struct tree *root = read_tree();

    if (root == NULL)
    {
        printf("Chyba pri nacitani databazy pravidiel.\n");
        return 1;
    }

    interact(root);
    free_tree(root);

    return 0;
}