refactor: Replace 结点 with 节点 (#452)

* Replace 结点 with 节点
Update the footnotes in the figures

* Update mindmap

* Reduce the size of the mindmap.png

codes/python/chapter_tree/binary_tree_bfs.py

@@ -11,18 +11,18 @@ from collections import deque
 
 def level_order(root: TreeNode | None) -> list[int]:
     """ 层序遍历 """
-    # 初始化队列，加入根结点
+    # 初始化队列，加入根节点
     queue: deque[TreeNode] = deque()
     queue.append(root)
     # 初始化一个列表，用于保存遍历序列
     res: list[int] = []
     while queue:
         node: TreeNode = queue.popleft() # 队列出队
-        res.append(node.val)             # 保存结点值
+        res.append(node.val)             # 保存节点值
         if node.left is not None:
-            queue.append(node.left)      # 左子结点入队
+            queue.append(node.left)      # 左子节点入队
         if node.right is not None:
-            queue.append(node.right)     # 右子结点入队
+            queue.append(node.right)     # 右子节点入队
     return res
 
 
@@ -36,5 +36,5 @@ if __name__ == "__main__":
 
     # 层序遍历
     res: list[int] = level_order(root)
-    print("\n层序遍历的结点打印序列 = ", res)
+    print("\n层序遍历的节点打印序列 = ", res)
     assert res == [1, 2, 3, 4, 5, 6, 7]