usaa21/cv8/program.c

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#define SIZE 50
struct tree{
    char question[SIZE];
    struct tree* left;
    struct tree* right;
};

struct tree* read_tree();
void system_execute(struct tree* root);
int get_input(char *string);
int type_count(struct tree* root);
void destroy_tree(struct tree* root);


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

    char resp[SIZE];
    memset(resp,0,SIZE);
    get_input(resp);
    if(strlen(resp)>1){
        printf("Expert z bufetu to vie.");
        puts("Chybna databaza");
        exit(0);
    }


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

    system_execute(root);

    getchar();
    printf("Koniec\n");

    destroy_tree(root);

    return 0;
}


struct tree* read_tree(){
    char buffer[SIZE];
    memset(buffer,0,SIZE);

    int flag = get_input(buffer);
    if(flag==-1){
        printf("Expert z bufetu to vie.");
        puts("Chybna databaza");
        exit(0);
    }

    struct tree* node = calloc(1,sizeof(struct tree));
    memcpy(node->question,buffer,SIZE);
    if(node->question[0]!='*'){
        node->left = read_tree();
        node->right = read_tree();
    }
    return node;
}


int get_input(char *string){
    char* r = fgets(string,SIZE,stdin);
    if(r==NULL){
        return -1;//EOF
    }
    string[strlen(string)-1]='\0';
    return 1;
}


void system_execute(struct tree* root){
    if(root==NULL){
        return;
    }
    printf("%s\n",root->question);
    if(root->question[0]=='*'){
        return;
    }
    char *resp = calloc(SIZE,sizeof(char));

    int flag = get_input(resp);
    if(flag==-1){
        puts("Koniec vstupu");
        exit(0);
    }
    if(resp[0]=='a'){
        system_execute(root->left);
    }else if(resp[0]=='n'){
        system_execute(root->right);
    }else{
        puts("Nerozumiem");
        exit(0);
    }
}


int type_count(struct tree* root){
    if(root==NULL){
        return 0;
    }
    if(root->question[0]=='*'){
        return 1;
    }
    int count= type_count(root->left)+type_count(root->right);
    return count;
}

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