Merge pull request gzc426#332 from ouyawen2016/patch-2

gzc426 · web-flow · commit f06eb0e4ca72 · 2018-12-06T22:08:11.000+08:00
Create oven123.md
diff --git a/2018.12.4-leetcode101/oven123.md b/2018.12.4-leetcode101/oven123.md
@@ -0,0 +1,30 @@
+```java
+
+/**
+ * Definition for a binary tree node.
+ * public class TreeNode {
+ *     int val;
+ *     TreeNode left;
+ *     TreeNode right;
+ *     TreeNode(int x) { val = x; }
+ * }
+ */
+class Solution {
+    public boolean isSymmetric(TreeNode root) {
+      
+        return compareTree(root,root);
+    }
+    boolean compareTree(TreeNode tree1,TreeNode tree2){
+        if(tree1==null&&tree2==null)//递归到最内层同时为空
+            return true;
+        if(tree1==null||tree2==null)//如果有其中一个为空但另一个不为空
+            return false;
+        return(tree1.val==tree2.val)
+          &&compareTree(tree1.left,tree2.right)
+            &&compareTree(tree1.right,tree2.left); 
+        
+           
+    }
+}
+
+```
