From c915f50377b7b16ad199210a88334f047c635704 Mon Sep 17 00:00:00 2001
From: SavelevMI <maksim.savelev2004maksim@gmail.com>
Date: Thu, 21 May 2026 13:37:55 +0000
Subject: [PATCH] [1] Implement binary search tree (BST) for phonebook

---
 SavelevMI/docs/data/1-st-exersize/bst.py | 66 ++++++++++++++++++++++++
 1 file changed, 66 insertions(+)
 create mode 100644 SavelevMI/docs/data/1-st-exersize/bst.py

diff --git a/SavelevMI/docs/data/1-st-exersize/bst.py b/SavelevMI/docs/data/1-st-exersize/bst.py
new file mode 100644
index 0000000..70d2952
--- /dev/null
+++ b/SavelevMI/docs/data/1-st-exersize/bst.py
@@ -0,0 +1,66 @@
+# Двоичное дерево поиска (не сбалансированное)
+
+def create_node(name, phone):
+    return {'name': name, 'phone': phone, 'left': None, 'right': None}
+
+def bst_insert(root, name, phone):
+    if root is None:
+        return create_node(name, phone)
+
+    if name == root['name']:
+        root['phone'] = phone
+    elif name < root['name']:
+        root['left'] = bst_insert(root['left'], name, phone)
+    else:
+        root['right'] = bst_insert(root['right'], name, phone)
+    return root
+
+def bst_find(root, name):
+    if root is None:
+        return None
+    if name == root['name']:
+        return root['phone']
+    elif name < root['name']:
+        return bst_find(root['left'], name)
+    else:
+        return bst_find(root['right'], name)
+
+def _find_min(node):
+    while node['left'] is not None:
+        node = node['left']
+    return node
+
+def bst_delete(root, name):
+    if root is None:
+        return None
+
+    if name < root['name']:
+        root['left'] = bst_delete(root['left'], name)
+    elif name > root['name']:
+        root['right'] = bst_delete(root['right'], name)
+    else:
+        # Нашли узел, который нужно удалить
+        if root['left'] is None:
+            return root['right']
+        if root['right'] is None:
+            return root['left']
+
+        # Узел имеет двух потомков: заменяем наименьшим из правого поддерева
+        min_node = _find_min(root['right'])
+        root['name'] = min_node['name']
+        root['phone'] = min_node['phone']
+        root['right'] = bst_delete(root['right'], min_node['name'])
+    return root
+
+def bst_list_all(root):
+    result = []
+
+    def inorder(node):
+        if node is None:
+            return
+        inorder(node['left'])
+        result.append((node['name'], node['phone']))
+        inorder(node['right'])
+
+    inorder(root)
+    return result
\ No newline at end of file