Implement a function to validate that a binary tree is a binary search tree.

validateBST.ts

// Valiate binary tree: Implement a function to validate that a binary tree is a binary search tree.

function validateBST<T>(node: BinaryNode<T>) {
  if (!node) return true
  if (node.leftChild && node.leftChild.data > node.data) return false
  if (node.rightChild && node.rightChild.data < node.data) return false
  return validateBST(node.leftChild) && validateBST(node.rightChild)
}