leetcode

Author: “wangruiguo”

二叉树/order_loop.py

@@ -0,0 +1,34 @@
+
+from tree_struct import build_tree
+
+class Solution:
+    
+    def order_loop(self, root):
+        """
+        递归方法:
+        1.创建结果列表
+        2.进行递归
+        """
+        def _recursion(node, ans_list):
+            """
+            递归逻辑:
+            1.递归参数返回，参数为node和结果列表，返回为结果列表
+            2.结束条件，当node为None时返回
+            3.递归逻辑：左右中
+            """
+            if not node:
+                return ans_list
+            ans_list = _recursion(node.left, ans_list)
+            ans_list = _recursion(node.right, ans_list)
+            ans_list.append(node.val)
+            return ans_list
+        ans_list = []
+        ans_list = _recursion(root, ans_list)
+        return ans_list
+
+if __name__ == '__main__':
+    vals_list = [1, None, 2, None, None, 3]
+    root = build_tree(vals_list)
+    s = Solution()
+    ans_list = s.order_loop(root)
+    print(f'ans_list: {ans_list}')