AVL Tree Example

main.c

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

#include "avl.h"

void avl_print (AVLNode *node) {

    if (node) {
        avl_print (node->right);

        if (node->id) printf ("Username: %s\n", ((User *) node->id)->name);

        avl_print (node->left);
    }

}

int main (void) {

    // create and initialize to default values our tree
    AVLTree *tree = avl_init (user_comparator, user_delete);

    User *erick = user_new ("erick", 1);    // we create a new user 
    avl_insert_node (tree, erick);          // insert the user into the tree

    User *luis = user_new ("luis", 2);      // we create a new user 
    avl_insert_node (tree, luis);           // insert the user into the tree

    User *isai = user_new ("isai", 3);      // we create a new user 
    avl_insert_node (tree, isai);           // insert the user into the tree

    avl_print (tree->root);

    // we can remove a node from the tree by passing a reference to its data
    // and the tree will use the comparator method to do its magic and return 
    // the data ptr if it exists, if not, it will return NULL
    User *luis_two = (User *) avl_remove_node (tree, luis);
    user_delete (luis_two);                 // we msut delete this ptr

    // we can use the comparator method and create a new user that we will use a query
    // and get data from the tree
    User *query = user_new ("erick", 2);
    void *found_ptr = avl_get_node_data (tree, query);
    if (found_ptr) {
        User *found = (User *) found_ptr;
        printf ("\nFound name: %s\n", found->name);
    }

    else printf ("\nNot found!!!\n");

    user_delete (query);                    // the query must be deleted aftyer use

    avl_print (tree->root);

    // remember to delete the tree after use to avoid memory leaks
    avl_delete (tree);

    return 0;

}