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#include "binary_tree.h"
#include <stdio.h>
#include <stdlib.h>
/**
* Initialize a new node for a Binary Tree.
*
* @param data the data to assign to the root of the tree.
* @return The root of the binary tree.
*/
Node *initialize(int data) {
Node *item = malloc(sizeof(Node));
item->data = data;
item->left = NULL;
item->right = NULL;
return item;
}
/*
* Traverses a binary tree using the traversal algorithm specified.
* Time: O(n)
* Space: O(1)
*
* @param node The root of the binary tree
* @param vistior A callback function to invoke on each node during the tree
* traversal
* @param traversal Specifies what type of traversal to perform
*/
void traverse(Node *node, Visitor visitor, enum Traversal traversal) {
if (!node)
return;
switch (traversal) {
case PREORDER:
visitor(node);
traverse(node->left, visitor, traversal);
traverse(node->right, visitor, traversal);
break;
case INORDER:
traverse(node->left, visitor, traversal);
visitor(node);
traverse(node->right, visitor, traversal);
break;
case POSTORDER:
traverse(node->left, visitor, traversal);
traverse(node->right, visitor, traversal);
visitor(node);
break;
default:
visitor(node);
break;
}
}
/**
* Frees the memory allocated for a node in a tree
*
* @param node The node in the binary tree to free
*/
static void destructor(Node *node) { free(node); }
/**
* Frees the memory associated with each node in a binary tree.
*
* @param root The root of the tree
*/
void destroy(Node *root) { traverse(root, destructor, POSTORDER); }
/**
* A helper method to print out a visual representation of the tree
*
* @param node A node in a binary tree.
* @param level The level in the tree that the node is at
*/
void inspect(Node *node, int level) {
if (!node)
return;
for (int i = 0; i < level; i++)
printf(" ");
printf("(%d)\n", node->data);
inspect(node->left, level + 1);
inspect(node->right, level + 1);
}
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