101. Symmetric Tree

Practice Symmetric Tree for free on NudgeCode: Easy, Binary Tree pattern. Write it in Python or JavaScript, run the tests in your browser, and ask for a hint when you are stuck.

Decide whether a binary tree is a mirror image of itself: fold it down the middle and every node on the left must land on a node with the same value on the right. An empty tree counts as symmetric.

Trees are written in level order, with null for a missing child.

Example

root = [1,2,2,3,4,4,3]  ->  true
root = [1,2,2,null,3,null,3]  ->  false

Constraints

• 0 <= number of nodes <= 1000
• -100 <= Node.val <= 100