freshlybakedca.ke
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1/*
2 * Copyright 2020 Google LLC
3 *
4 * Use of this source code is governed by a BSD-style
5 * license that can be found in the LICENSE file or at
6 * https://developers.google.com/open-source/licenses/bsd
7 */
8
9#ifndef TREE_H
10#define TREE_H
11
12/* tree_node is a generic binary search tree. */
13struct tree_node {
14 void *key;
15 struct tree_node *left, *right;
16};
17
18/*
19 * Search the tree for the node matching the given key using `compare` as
20 * comparison function. Returns the node whose key matches or `NULL` in case
21 * the key does not exist in the tree.
22 */
23struct tree_node *tree_search(struct tree_node *tree,
24 void *key,
25 int (*compare)(const void *, const void *));
26
27/*
28 * Insert a node into the tree. Returns the newly inserted node if the key does
29 * not yet exist. Otherwise it returns the preexisting node. Returns `NULL`
30 * when allocating the new node fails.
31 */
32struct tree_node *tree_insert(struct tree_node **rootp,
33 void *key,
34 int (*compare)(const void *, const void *));
35
36/* performs an infix walk of the tree. */
37void infix_walk(struct tree_node *t, void (*action)(void *arg, void *key),
38 void *arg);
39
40/*
41 * deallocates the tree nodes recursively. Keys should be deallocated separately
42 * by walking over the tree. */
43void tree_free(struct tree_node *t);
44
45#endif