From 3efcaa6dfcd14ab809f85dec7220429a38f9db58 Mon Sep 17 00:00:00 2001
From: Joshua <47053655+Joshua-Lu@users.noreply.github.com>
Date: Fri, 14 May 2021 01:09:44 +0800
Subject: [PATCH] =?UTF-8?q?Update=200226.=E7=BF=BB=E8=BD=AC=E4=BA=8C?=
 =?UTF-8?q?=E5=8F=89=E6=A0=91.md?=
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添加 0226.翻转二叉树.md Java版本
---
 problems/0226.翻转二叉树.md | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/problems/0226.翻转二叉树.md b/problems/0226.翻转二叉树.md
index f5626ea0..dc29a965 100644
--- a/problems/0226.翻转二叉树.md
+++ b/problems/0226.翻转二叉树.md
@@ -203,7 +203,29 @@ public:
 
 
 Java：
+```Java
+class Solution {
+   /**
+     * 前后序遍历都可以
+     * 中序不行，因为先左孩子交换孩子，再根交换孩子（做完后，右孩子已经变成了原来的左孩子），再右孩子交换孩子（此时其实是对原来的左孩子做交换）
+     */
+    public TreeNode invertTree(TreeNode root) {
+        if (root == null) {
+            return null;
+        }
+        invertTree(root.left);
+        invertTree(root.right);
+        swapChildren(root);
+        return root;
+    }
 
+    private void swapChildren(TreeNode root) {
+        TreeNode tmp = root.left;
+        root.left = root.right;
+        root.right = tmp;
+    }
+}
+```
 
 Python：