Initializtion

a3/binary_search_tree.c

@@ -29,6 +29,10 @@ node_t *build_tree(int *tree_data, size_t tree_data_len) {
         }
 
         current = malloc(sizeof(node_t));
+        if (current == NULL) {
+            free_tree(root);
+            return NULL;
+        }
         current->data = tree_data[i];
         current->left = NULL;
         current->right = NULL;