usaa21/cv8/program.c

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


/**
 * A structure, representing a single node (fruit/vegetable) and it's children nodes
 */
struct binary{
    char value[120];
    struct binary* left;
    struct binary* right;
};


/**
 * A global boolean variable that shows if the end of the binary tree was found.
 * It's a very important one, as there's a constant need of such information
 */
bool endingFound = false;


/**
 * This function is used to create and initialize a new binary tree
 * @param name – a name of the product that will become the first node of a newly created binary tree.
 * @return – a pointer to the newly created binary tree.
 */
struct binary* createBinary(char* name){
    struct binary* newTree = (struct binary*)calloc(1, sizeof(struct binary));
    strcpy(newTree->value, name);
    newTree->left = NULL;
    newTree->right = NULL;
    return newTree;
}


/**
 * The function recursively iterated through the whole binary tree until it finds a place to add new node to. Once the
 * place is found, it created a new node with a given value.
 * @param myTree – a pointer to the binary tree that the new node should be appended to.
 * @param product – a name of the product that will be added as a new node.
 * @return – NULL if the node was not yet added, pointer to the new node if the node was added.
 */
struct binary* productAppend(struct binary* myTree, char* product){
    if(!myTree || (myTree->right != NULL && myTree->left != NULL) && (myTree->left->value[0] == '*' && myTree->right->value[0] == '*'))
        return NULL;

    struct binary* itrNode = myTree;
    while(itrNode->left != NULL){
        if(itrNode->left->value[0] != '*')
            itrNode = (!productAppend(itrNode->left, product)) ? itrNode : productAppend(itrNode->left, product);
        if(endingFound || !itrNode->right || !itrNode->left)
            break;
        if(itrNode->right->value[0] != '*')
            itrNode = (!productAppend(itrNode->right, product)) ? itrNode : productAppend(itrNode->right, product);
    }

    if(!endingFound && !itrNode->left) {
        itrNode->left = createBinary(product);
        endingFound = true;
        return itrNode;
    }
    else if(!endingFound && !itrNode->right){
        itrNode->right = createBinary(product);
        endingFound = true;
        return itrNode;
    }

    return NULL;
}


/**
 *
 * @param myTree – a pointer to the binary tree that the new question should be appended to.
 * @param question – the text of a question to be added as a new node.
 * @return – a pointer to the newly created node in case function runs successfully, NULL otherwise.
 */
struct binary* questionAppend(struct binary* myTree, char* question){
    struct binary* itrNode1 = myTree;
    struct binary* itrNode2 = myTree;

    while(itrNode1->left && itrNode1->right && itrNode2->left && itrNode2->right){
        if(itrNode1->left->value[0] != '*')
            itrNode1 = questionAppend(itrNode1->left, question);
        if(endingFound)
            break;
        if(itrNode2->right->value[0] != '*')
            itrNode2 = questionAppend(itrNode2->right, question);
    }

    if(!itrNode1->left) {
        itrNode1->left = createBinary(question);
        endingFound = true;
        return itrNode1;
    }
    else if(!itrNode1->right){
        itrNode1->right = createBinary(question);
        endingFound = true;
        return itrNode1;
    }
    else if(!itrNode2->left && !endingFound){
        itrNode2->left = createBinary(question);
        endingFound = true;
        return itrNode2;
    }
    else if(!itrNode2->right && !endingFound){
        itrNode2->right = createBinary(question);
        endingFound = true;
        return itrNode2;
    }

    return NULL;
}


int main() {
    char* usrIn = (char*)calloc(120, sizeof(char));
    struct binary* binaryTree;
    struct binary* itrNode;
    char* usrResponse = (char*)calloc(10, sizeof(char));
    int inputsAmount = 0;

    for(int i = 0; fgets(usrIn, 120, stdin); i++){
        if(!usrIn || !strcmp(usrIn, "") || !strcmp(usrIn, " ") || !strcmp(usrIn, "\n"))
            break;

        usrIn[strlen(usrIn) - 1] = '\0';
        if(i == 0){
            binaryTree = createBinary(usrIn);
            itrNode = binaryTree;
        }
        else{
            if(usrIn[0] == '*')
                inputsAmount++;
            if(strlen(usrIn) > 1)
                productAppend(itrNode, usrIn);
            endingFound = false;
        }
    }

    printf("Expert z bufetu to vie.\n");
    printf("Pozna %d druhov ovocia a zeleniny.\n", inputsAmount);
    printf("Odpovedajte 'a' pre prvu moznost alebo 'n' pre druhu moznost.\n");

    while(binaryTree->value[0] != '*'){
        printf("%s\n", binaryTree->value);
        scanf("%s", usrResponse);
        if(strlen(usrResponse) == 0){
            printf("Koniec vstupu\n");
            return 0;
        }
        if (strlen(usrResponse) == 1) {
            if (tolower(usrResponse[0]) == 'a')
                binaryTree = binaryTree->left;
            else if (tolower(usrResponse[0] == 'n'))
                binaryTree = binaryTree->right;
            else {
                printf("Nerozumiem\n");
                return 0;
            }
        }
        else{
            printf("Nerozumiem\n");
            return 0;
        }
    }
    printf("%s\n", binaryTree->value);
    printf("Koniec\n");

    return 0;
}