From: Elias Fleckenstein <eliasfleckenstein@web.de>
Date: Fri, 24 Sep 2021 12:33:18 +0000 (+0200)
Subject: Add binary tree traversion
X-Git-Url: https://git.lizzy.rs/?a=commitdiff_plain;h=0a84db35735a112a12f026f871a730706aff1aeb;p=dragonstd.git

Add binary tree traversion
---

diff --git a/bintree.c b/bintree.c
index 6587e12..f21403a 100644
--- a/bintree.c
+++ b/bintree.c
@@ -2,6 +2,12 @@
 #include <stdlib.h>
 #include "bintree.h"
 
+typedef struct
+{
+	BintreeTraversionFunction func;
+	void *arg;
+} BintreeFreeData;
+
 static int bintree_compare_mem(void *v1, void *v2, Bintree *tree)
 {
 	return memcmp(v1, v2, tree->key_size);
@@ -46,22 +52,49 @@ void bintree_add_node(Bintree *tree, BintreeNode **nodeptr, void *key, void *val
 	(*nodeptr)->left = (*nodeptr)->right = NULL;
 }
 
-static void free_recursive(BintreeNode *node, BintreeFreeFunction func, void *arg)
+static void bintree_free(BintreeNode *node, void *arg)
 {
-	if (node) {
-		free_recursive(node->left, func, arg);
-		free_recursive(node->right, func, arg);
-		free(node->key);
-		if (func)
-			func(node->value, arg);
-		free(node);
-	}
+	BintreeFreeData *fdata = arg;
+
+	if (fdata->func)
+		fdata->func(node, fdata->arg);
+
+	free(node->key);
+	free(node);
 }
 
-void bintree_clear(Bintree *tree, BintreeFreeFunction func, void *arg)
+void bintree_clear(Bintree *tree, BintreeTraversionFunction func, void *arg)
 {
 	if (tree) {
-		free_recursive(tree->root, func, arg);
+		BintreeFreeData fdata = {
+			.func = func,
+			.arg = arg,
+		};
+
+		bintree_traverse(tree, BTT_POSTORDER, &bintree_free, &fdata);
 		tree->root = NULL;
 	}
 }
+
+static void traverse_recursive(BintreeNode *node, BintreeTraversion traversion, BintreeTraversionFunction func, void *arg)
+{
+	if (node) {
+		if (traversion == BTT_PREORDER)
+			func(node, arg);
+
+		traverse_recursive(node->left, traversion, func, arg);
+
+		if (traversion == BTT_INORDER)
+			func(node, arg);
+
+		traverse_recursive(node->right, traversion, func, arg);
+
+		if (traversion == BTT_POSTORDER)
+			func(node, arg);
+	}
+}
+
+void bintree_traverse(Bintree *tree, BintreeTraversion traversion, BintreeTraversionFunction func, void *arg)
+{
+	traverse_recursive(tree->root, traversion, func, arg);
+}
diff --git a/bintree.h b/bintree.h
index 9dd0cfa..36099f1 100644
--- a/bintree.h
+++ b/bintree.h
@@ -5,9 +5,6 @@
 
 struct Bintree;
 
-typedef int (*BintreeComparator)(void *v1, void *v2, struct Bintree *tree);
-typedef void (*BintreeFreeFunction)(void *value, void *arg);
-
 typedef struct BintreeNode
 {
 	void *key;
@@ -16,6 +13,9 @@ typedef struct BintreeNode
 	struct BintreeNode *right;
 } BintreeNode;
 
+typedef int (*BintreeComparator)(void *v1, void *v2, struct Bintree *tree);
+typedef void (*BintreeTraversionFunction)(BintreeNode *node, void *arg);
+
 typedef struct Bintree
 {
 	BintreeNode *root;
@@ -23,9 +23,17 @@ typedef struct Bintree
 	BintreeComparator cmp;
 } Bintree;
 
+typedef enum
+{
+	BTT_PREORDER,
+	BTT_INORDER,
+	BTT_POSTORDER,
+} BintreeTraversion;
+
 Bintree bintree_create(size_t key_size, BintreeComparator cmp);
 BintreeNode **bintree_search(Bintree *tree, void *key);
 void bintree_add_node(Bintree *tree, BintreeNode **nodeptr, void *key, void *value);
-void bintree_clear(Bintree *tree, BintreeFreeFunction func, void *arg);
+void bintree_traverse(Bintree *tree, BintreeTraversion traversion, BintreeTraversionFunction func, void *arg);
+void bintree_clear(Bintree *tree, BintreeTraversionFunction func, void *arg);
 
 #endif