vamsitallapudi · December 18, 2020 11:31
diff --git a/PreOrderTraversal.kt b/PreOrderTraversal.kt
    fun preorderTraversal(root: TreeNode?): List<Int> {
 //        if root is null, return list of empty array
        if (root == null) {
            return listOf()
        }
 //        iterate recursively into left child and right child
        return listOf(root.data) + preorderTraversal(root.left) + preorderTraversal(root.right)
    }
	fun preorderTraversal(root: TreeNode?): List<Int> {
	// if root is null, return list of empty array
	if (root == null) {
	return listOf()
	}
	// iterate recursively into left child and right child
	return listOf(root.data) + preorderTraversal(root.left) + preorderTraversal(root.right)
	}