usaa20/cv8/program.c

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

struct tree {
    char value[50];
    struct tree* left;
    struct tree* right;
};


struct tree* read_tree(){
    char buffer[50];
    memset(buffer,0,50);
    char* r = fgets(buffer,50,stdin);
    int x = strlen(buffer);
    buffer[x-1]='\0'; 
    
    assert(r);
    
    if(buffer[0] != '\0'){
        struct tree* node = calloc(1,sizeof(struct tree));
        memcpy(node->value, buffer,50);
        if(buffer[0] != '*'){ 
            if(node->left == NULL){
                node->left = read_tree();   
            }
            if(node->right == NULL){    
                node->right = read_tree();
            }
        }
        return node;
    }

}
struct tree* search(struct tree* this){
    
    int c = getchar();
        if(this == NULL || this->value[0] == '*'){
            return this;
        } 
     
        if(c == 'a'){
            printf("%s\n", this->left->value);
            return search(this->left);
        }
        else if(c == 'n'){ 
            printf("%s\n", this->right->value);
            return search(this->right); 
        } 
}

void print_tree(struct tree* tree,int offset){
    int i;
    for (i = 0; i < offset; i++){
        printf(" ");
    }
    printf("%s",tree->value);
    if (tree->left){
        print_tree(tree->left,offset +3);
        print_tree(tree->right,offset +3);
    }
} 

struct tree* find_minimum(struct tree *root){
    if(root == NULL){
        return NULL;
    }
    else if(root->left != NULL){
        return find_minimum(root->left); 
    }
    return root;
}


struct tree* destroy_tree(struct tree* root){
    if(root == NULL) return;
     
    if(root->left == NULL && root->right == NULL){
        free(root);
        return NULL;
    }
    else if(root->left == NULL || root->right == NULL){
        struct tree* temp;
        if(root->left == NULL){
            temp = root->right;
        }else{
            temp = root->left;
        }
        free(root);
        return temp; 
    }
    else {
        struct tree* this = find_minimum(root->left);
        strcpy(root->value, this->value);
        root->right = destroy_tree(root->right);
    }
    root->left = destroy_tree(root->left);
    root->right = destroy_tree(root->right);   
    free(root);
    root = NULL;
}
int count_leaves(struct tree* node){
    int count = 0;
    if(node->left == NULL && node->right == NULL){
        count = 1;
    } 
    else{
        if(node->left != NULL){
            count += count_leaves(node->left);
        }
        if(node->right != NULL){
            count += count_leaves(node->right);
        }   
    }
    return count;

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


int main(){
    struct tree* tree = NULL;
    tree = read_tree();
    int count = count_leaves(tree);
    //print_tree(tree, 3); 
    printf("Expert z bufetu to vie.\n");
    printf("Pozna %d druhov ovocia a zeleniny.\n", count);
    printf("Odpovedajte 'a' pre prvu moznost alebo 'n' pre druhu moznost.\n");
    printf("%s\n", tree->value);   
    tree = search(tree);   
    destroy_tree(tree);
    printf("Koniec\n");     
    return 0;
}