feat(tree): implement free function

src/tree/node.c

@@ -4,6 +4,8 @@ vieter_tree_node *vieter_tree_node_init() {
   return calloc(1, sizeof(vieter_tree_node));
 }
 
+void vieter_tree_node_free(vieter_tree_node *node) { free(node); }
+
 void vieter_tree_node_add_child(vieter_tree_node *parent, uint64_t key,
                                 vieter_tree_node *child) {
   if (parent == NULL) {
@@ -121,17 +123,17 @@ vieter_tree_error vieter_tree_node_remove(void **out, vieter_tree_node *root,
   if (target->left == NULL && target->right == NULL) {
     vieter_tree_node_add_child(target->parent, target->key, NULL);
 
-    free(target);
+    vieter_tree_node_free(target);
   } else if ((target->left == NULL) ^ (target->right == NULL)) {
     vieter_tree_node *child =
         target->left != NULL ? target->left : target->right;
 
     if (target->parent != NULL) {
       vieter_tree_node_add_child(target->parent, child->key, child);
-      free(target);
+      vieter_tree_node_free(target);
     } else {
       vieter_tree_node_replace(target, child);
-      free(child);
+      vieter_tree_node_free(child);
     }
 
   } else {
@@ -151,7 +153,7 @@ vieter_tree_error vieter_tree_node_remove(void **out, vieter_tree_node *root,
     target->key = replacement->key;
     target->data = replacement->data;
 
-    free(replacement);
+    vieter_tree_node_free(replacement);
   }
 
   return vieter_tree_ok;

src/tree/node.h

@@ -14,6 +14,8 @@ typedef struct vieter_tree_node {
 
 vieter_tree_node *vieter_tree_node_init();
 
+void vieter_tree_node_free(vieter_tree_node *node);
+
 vieter_tree_error vieter_tree_node_insert(vieter_tree_node *root, uint64_t key, void *data);
 
 vieter_tree_error vieter_tree_node_search_node(vieter_tree_node **out, vieter_tree_node *root, uint64_t key);
@@ -21,8 +23,6 @@ vieter_tree_error vieter_tree_node_search(void **out, vieter_tree_node *root, ui
 
 vieter_tree_error vieter_tree_node_remove(void **out, vieter_tree_node *root, uint64_t key);
 
-vieter_tree_node *vieter_tree_node_successor(vieter_tree_node *node);
-
 void vieter_tree_node_replace(vieter_tree_node *to_replace, vieter_tree_node *replacement);
 
 #endif

src/tree/tree.c

@@ -57,3 +57,43 @@ vieter_tree_error vieter_tree_remove(void **out, vieter_tree *tree,
 
   return vieter_tree_ok;
 }
+
+void vieter_tree_free(vieter_tree *tree) {
+  if (tree->size == 0) {
+    goto end;
+  }
+
+  uint64_t capacity = 4;
+  uint64_t size = 1;
+  vieter_tree_node **stack = malloc(capacity * sizeof(vieter_tree_node *));
+  stack[0] = tree->root;
+
+  vieter_tree_node *node;
+
+  while (size > 0) {
+    node = stack[size - 1];
+    size--;
+
+    if (size + 2 > capacity) {
+      capacity *= 2;
+      stack = realloc(stack, capacity * sizeof(vieter_tree_node *));
+    }
+
+    if (node->left != NULL) {
+      stack[size] = node->left;
+      size++;
+    }
+
+    if (node->right != NULL) {
+      stack[size] = node->right;
+      size++;
+    }
+
+    vieter_tree_node_free(node);
+  }
+
+  free(stack);
+
+end:
+  free(tree);
+}

test/tree/test_binary_tree.c

@@ -9,7 +9,7 @@ void test_init() {
     vieter_tree *tree = vieter_tree_init();
     TEST_CHECK(tree != NULL);
     TEST_SIZE(tree, 0);
-    /* vieter_tree_free(tree); */
+    vieter_tree_free(tree);
 }
 
 void test_insert() {
@@ -27,6 +27,8 @@ void test_insert() {
         TEST_CHECK(vieter_tree_insert(tree, i, NULL) == vieter_tree_already_present);
         TEST_CHECK(vieter_tree_search(&out, tree, i) == vieter_tree_ok);
     }
+
+    vieter_tree_free(tree);
 }
 
 void test_remove() {
@@ -42,7 +44,10 @@ void test_remove() {
         TEST_CHECK(vieter_tree_search(&out, tree, i) == vieter_tree_ok);
         TEST_CHECK(vieter_tree_remove(&out, tree, i) == vieter_tree_ok);
         TEST_CHECK(vieter_tree_search(&out, tree, i) == vieter_tree_not_present);
+        TEST_SIZE(tree, 25 - i - 1);
     }
+
+    vieter_tree_free(tree);
 }
 
 TEST_LIST = {