From c51ba17dc0baaf381d3bc5d9c72ff043060e27a0 Mon Sep 17 00:00:00 2001
From: Nezuko-Wen <409053122@qq.com>
Date: Sat, 5 Dec 2020 17:36:05 +0800
Subject: [PATCH] =?UTF-8?q?=E5=AF=B9=E7=A7=B0=E7=9A=84=E4=BA=8C=E5=8F=89?=
 =?UTF-8?q?=E6=A0=91?=
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---
 src/offer/Question28.java | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)
 create mode 100644 src/offer/Question28.java

diff --git a/src/offer/Question28.java b/src/offer/Question28.java
new file mode 100644
index 0000000..f6461b2
--- /dev/null
+++ b/src/offer/Question28.java
@@ -0,0 +1,34 @@
+package offer;
+
+import leecode.tree.TreeNode;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Objects;
+import java.util.Stack;
+
+/**
+ * 对称的二叉树
+ */
+public class Question28 {
+    public boolean isSymmetry(TreeNode node) {
+        TreeNode lHead = new TreeNode(0);
+        lHead.left = node;
+        TreeNode rHead = new TreeNode(0);
+        rHead.left = node;
+        return dfs(lHead.left, rHead.left);
+    }
+
+    private boolean dfs(TreeNode lHead, TreeNode rHead) {
+        if (lHead == null && rHead == null) {
+            return true;
+        }
+        if (lHead == null || rHead == null) {
+            return false;
+        }
+        if (!Objects.equals(lHead.val, rHead.val)) {
+            return false;
+        }
+        return dfs(lHead.left, rHead.right) && dfs(lHead.right, rHead.left);
+    }
+}