From 202832f29cc56dff3210f28e3361cc185e96ffae Mon Sep 17 00:00:00 2001
From: wjf-hs <Orig5826@163.com>
Date: Mon, 24 Jun 2024 10:15:54 +0800
Subject: [PATCH] =?UTF-8?q?balance=3D0=E6=97=B6=E4=B8=8D=E9=9C=80=E8=A6=81?=
 =?UTF-8?q?=E6=97=8B=E8=BD=AC?=
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---
 include/tree.h   |  4 ++--
 src/tree.c       | 32 ++++++++------------------------
 test/test_tree.c |  4 ++--
 3 files changed, 12 insertions(+), 28 deletions(-)

diff --git a/include/tree.h b/include/tree.h
index 9d213b6..9b823d3 100644
--- a/include/tree.h
+++ b/include/tree.h
@@ -83,7 +83,7 @@ struct _tree_node
 
     union 
     {
-        uint32_t balance;
+        int32_t balance;
         uint32_t color;
     };
 };
@@ -108,7 +108,7 @@ struct _tree
     struct _tree_node* (*find_max)(struct _tree* self, struct _tree_node* root);
 
     bool (*rebalance)(struct _tree* self, struct _tree_node* root);
-    uint32_t (*height)(struct _tree* self, struct _tree_node* root);
+    int32_t (*height)(struct _tree* self, struct _tree_node* root);
 
     bool (*min)(struct _tree* self, void** obj);
     bool (*max)(struct _tree* self, void** obj);
diff --git a/src/tree.c b/src/tree.c
index 85f1342..01aa2a2 100644
--- a/src/tree.c
+++ b/src/tree.c
@@ -1502,7 +1502,7 @@ static struct _tree_node* tree_trun_right_then_left(struct _tree* self, struct _
     return node;
 }
 
-uint32_t tree_height(struct _tree* self, struct _tree_node* root)
+int32_t tree_height(struct _tree* self, struct _tree_node* root)
 {
     assert(self != NULL);
     if(root == NULL)
@@ -1544,7 +1544,11 @@ static bool tree_avl_rebalance(struct _tree* self, struct _tree_node* root)
     
     tree_set_balance(self, root);
     int balance = root->balance;
-    if(balance > 1)
+    if(balance == 0)
+    {
+        // no need to rebalance
+    }
+    else if(balance > 1)
     {
         if(root->right->balance > 0)
         {
@@ -1806,34 +1810,14 @@ bool tree_avl_delete(struct _tree* self, void* obj)
 
     if(node->left != NULL && node->right != NULL)
     {
+        // have two child
         tree_avl_delete_double_child(self, node);
     }
     else
-    // else if(node->left != NULL || node->right != NULL)
     {
+        // have singule child or no child
         tree_avl_delete_single_child(self, node);
     }
-    // else
-    // {
-    //     if(node->parent == NULL)
-    //     {
-    //         self->_root = NULL;
-    //     }
-    //     else
-    //     {
-    //         if(node->parent->left == node)
-    //         {
-    //             node->parent->left = NULL;
-    //         }
-    //         else if(node->parent->right == node)
-    //         {
-    //             node->parent->right = NULL;
-    //         }
-
-    //         self->rebalance(self, node->parent);
-    //     }
-    //     tree_node_free(node);
-    // }
 
     self->_size--;
     return true;
diff --git a/test/test_tree.c b/test/test_tree.c
index 2fc1c55..6af1fbb 100644
--- a/test/test_tree.c
+++ b/test/test_tree.c
@@ -344,13 +344,13 @@ void test_tree_num(void)
     for (i = 0; i < len; i++)
     {
         temp = data[i];
-        tree->delete(tree, &temp);
 
         printf("delete = ");
         tree->print_obj(&temp);
-
         printf("size = %2d\n", tree->size(tree));
 
+        tree->delete(tree, &temp);
+
         printf("----- breadth -----\n");
         tree->breadth(tree, tree->_root);
         printf("----- inorder -----\n");