101. Symmetric Tree (java)

Author: bluesword12350

solution/0101.Symmetric Tree/Solution.java

@@ -0,0 +1,12 @@
+class Solution {
+    public boolean isSymmetric(TreeNode root) {
+        if(root == null) return true;
+        return isSymmetric(root.left, root.right);
+    }
+    public boolean isSymmetric(TreeNode leftNode, TreeNode rightNode) {
+        if(leftNode == null && rightNode == null) return true;
+        if(leftNode == null || rightNode == null) return false;
+        return leftNode.val == rightNode.val && isSymmetric(leftNode.left, rightNode.right) &&
+                isSymmetric(leftNode.right, rightNode.left);
+    }
+}