Merge pull request gzc426#289 from MMzhe/patch-9

gzc426 · web-flow · commit d4524f6cd429 · 2018-12-03T19:45:09.000+08:00
Create sourcema.md
diff --git a/2018.12.04-leetcode101/sourcema.md b/2018.12.04-leetcode101/sourcema.md
@@ -0,0 +1,27 @@
+# LeetCode 101
+    /**
+     * 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) {
+            if (root == null) {
+                return true;
+            }
+            return symmetric(root.left, root.right);
+        }
+        private boolean symmetric(TreeNode p, TreeNode q) {
+            if (p == null && q == null) {
+                return true;
+            }
+            if ((p == null && q != null) || (p != null && q == null) || p.val != q.val) {
+                return false;
+            }
+            return symmetric(p.left, q.right) && symmetric(p.right, q.left);
+        }
+    }
