add binary_tree and avl_tree python code

codes/python/chapter_tree/binary_tree_bfs.py

@@ -1,10 +1,45 @@
-'''
+"""
 File: binary_tree_bfs.py
 Created Time: 2022-11-25
 Author: Krahets (krahets@163.com)
-'''
+"""
 
 import sys, os.path as osp
 sys.path.append(osp.dirname(osp.dirname(osp.abspath(__file__))))
 from include import *
 
+
+def hierOrder(root):
+    # 初始化队列，加入根结点
+    queue = collections.deque()
+    queue.append(root)
+    # 初始化一个列表，用于保存遍历序列
+    result = []
+    while queue:
+        # 队列出队
+        node = queue.popleft()
+        # 保存节点值
+        result.append(node.val)
+        if node.left is not None:
+            # 左子结点入队
+            queue.append(node.left)
+        if node.right is not None:
+            # 右子结点入队
+            queue.append(node.right)
+    return result
+
+
+""" Driver Code """
+if __name__ == "__main__":
+    # 初始化二叉树
+    # 这里借助了一个从数组直接生成二叉树的函数
+    root = list_to_tree(
+        arr=[1, 2, 3, 4, 5, 6, 7, None, None, None, None, None, None, None, None]
+    )
+    print("\n初始化二叉树\n")
+    print_tree(root)
+
+    # 层序遍历
+    result = hierOrder(root)
+    print("\n层序遍历的结点打印序列 = ", result)
+    assert result == [1, 2, 3, 4, 5, 6, 7]