C# recursive 76ms, faster than 100%
Runtime: 76 ms, faster than 100.00% of C# online submissions for Symmetric Tree.\nMemory Usage: 25.7 MB, less than 50.29% of C# online submissions for Symmetric
Runtime: 76 ms, faster than 100.00% of C# online submissions for Symmetric Tree.\nMemory Usage: 25.7 MB, less than 50.29% of C# online submissions for Symmetric Tree.\n```\npublic class Solution {\n    public bool IsSymmetric(TreeNode root) => CheckSymetry(root?.left, root?.right);\n    \n    private bool CheckSymetry(TreeNode left, TreeNode right)\n    {\n        if(left == null || right == null)\n            return left?.val == right?.val;\n        if(left.val != right.val)\n            return false;\n\n        return CheckSymetry(left.left, right.right) && CheckSymetry(left.right, right.left);\n    }\n}\n```
['C#']