python 层序遍历

codes/python/chapter_tree/binary_tree_bfs.py

@@ -5,6 +5,37 @@ Author: Krahets (krahets@163.com)
 """
 
 import sys, os.path as osp
-sys.path.append(osp.dirname(osp.dirname(osp.abspath(__file__))))
-from include import *
 
+from codes.python.include import *
+
+sys.path.append(osp.dirname(osp.dirname(osp.abspath(__file__))))
+
+# from include import *
+def levelOrder(root: [TreeNode]) -> list[list[int]]:
+
+    res = []
+    if not root:
+        return res
+    from collections import deque
+    q = deque([root])
+    while q:
+        list = []
+        size = len(q)
+        for _ in range(size):
+            cur = q.popleft()
+            list.append(cur.val)
+            if cur.left:
+                q.append(cur.left)
+            if cur.right:
+                q.append(cur.right)
+        res.append(list)
+    return res
+
+
+""" Driver Code """
+
+if __name__ == '__main__':
+    arr = [3, 9, 20, None, None, 15, 7]
+    root = list_to_tree(arr)
+    list = levelOrder(root)
+    print(list)