Given the root nodes of two binary trees, a and b, determine whether the two trees are equal.

Two binary trees are considered equal if they have the same structure and the corresponding nodes in both trees have the same values.

The binary tree is represented by a collection of TreeNodes, where each node has optional left and right child nodes, which are also TreeNodes.

A TreeNode has the following interface:

interface TreeNode {
  val: number;
  left: TreeNode | null;
  right: TreeNode | null;
}

Input

• a: TreeNode: Root node of the first tree. Examples display a level-order traversal of the tree
• b: TreeNode: Root node of the second tree. Examples display a level-order traversal of the tree

Input: a = [1,2], b = [1,null,2]
Output: false
Explanation: The trees differ in the structure.

Input: a = [3,null,7], b = [3,5,7]
Output: false
Explanation: The first tree has a null left child, while the second tree has a left child with value 5.

Input: a = [65,null,17], b = [65,null,17]
Output: true
Explanation: Both trees have the same structure and node values.

Constraints

• 0 <= Number of nodes <= 100
• -10,000 <= TreeNode.val <= 10,000