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#include "btree.h"
#include "stack.h"
#include <stdio.h>
/**
* Prints a visual representation of a binary tree
*
* @param tree The tree or subtree to print
* @param level The level in the tree that the subtree belongs to
*/
static void inspect(BTree *tree, int level) {
if (!tree)
return;
for (int i = 0; i < level; i++)
printf(" ");
printf("%2d\n", tree->data);
inspect(tree->left, level + 1);
inspect(tree->right, level + 1);
}
/**
* Initializes a new instance of a binary tree.
*
* @param data The data to bind to the root of the new subtree.
* @return Returns the new subtree.
*/
BTree *btree_init(int data) {
BTree *tree = malloc(sizeof(BTree));
tree->left = NULL;
tree->right = NULL;
tree->data = data;
return tree;
}
/**
* Performs and caches the result of a pre order traversal
* on a binary tree. Cached results are stored in the root of
* the tree and not on each node of the tree.
*
* @param tree The subtree to perform the traversal on
*/
void btree_pre_order_number(BTree *tree) {
BTree *original = tree;
if (tree == NULL)
return;
Stack *stack = stack_init();
int i = 0;
stack_push(stack, tree);
while (stack_size(stack) > 0) {
tree = stack_pop(stack);
original->pre_order[i++] = tree->data;
if (tree->right != NULL)
stack_push(stack, tree->right);
if (tree->left != NULL)
stack_push(stack, tree->left);
}
}
/**
* Performs and caches the result of an in order traversal
* on a binary tree. Cached results are stored in the root of
* the tree and not on each node of the tree.
*
* @param root The subtree to perform the traversal on
*/
void btree_in_order_number(BTree *root) {
BTree *original = root;
if (root == NULL)
return;
Stack *stack = stack_init();
int i = 0;
while (true) {
if (root) {
stack_push(stack, root);
root = root->left;
} else {
if (stack_size(stack) == 0)
break;
root = stack_pop(stack);
original->in_order[i++] = root->data;
root = root->right;
}
}
}
/**
* Performs and caches the result of an post order traversal
* on a binary tree. Cached results are stored in the root of
* the tree and not on each node of the tree.
*
* @param root The subtree to perform the traversal on
*/
void btree_post_order_number(BTree *root) {
BTree *original = root;
if (root == NULL)
return;
Stack *s1 = stack_init();
Stack *s2 = stack_init();
stack_push(s1, root);
while (stack_size(s1) > 0) {
root = stack_pop(s1);
stack_push(s2, root);
if (root->left)
stack_push(s1, root->left);
if (root->right)
stack_push(s1, root->right);
}
int i = 0;
while (stack_size(s2) > 0) {
root = stack_pop(s2);
original->post_order[i++] = root->data;
}
}
/**
* Insert a new items into a binary tree.
*
* @param tree The tree to insert the data into.
* @param data The data to insert into the tree.
* @return Returns the new root of the tree.
*/
BTree *btree_insert(BTree *tree, int data) {
if (!tree)
return btree_init(data);
if (data <= tree->data)
if (tree->left)
btree_insert(tree->left, data);
else
tree->left = btree_init(data);
else if (tree->right)
btree_insert(tree->right, data);
else
tree->right = btree_init(data);
return tree;
}
/**
* Prints a visual representation of a binary tree.
*
* @param tree The subtree to inspect.
*/
void btree_inspect(BTree *tree) { inspect(tree, 0); }
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