Create zjukk.md

zjukk · web-flow · commit b28b71007c89 · 2018-12-04T17:23:35.000+08:00
diff --git a/2018.12.4-leetcode101/zjukk.md b/2018.12.4-leetcode101/zjukk.md
@@ -0,0 +1,15 @@
+```
+class Solution {
+public:
+    bool isSymmetric(TreeNode* root) {
+        if (!root) return true;
+        return help(root->left,root->right);
+    }
+    bool help(TreeNode* left, TreeNode* right) {
+        if (!left && !right) return true;
+        if ((!left && right) || (left && !right)) return false;
+        if (left->val != right->val) return false;
+        else return help(left->left,right->right) && help(left->right,right->left);
+    }
+};
+```
