Inserting the keys in the order A X C S E R H into an

initially empty BST gives a worst$-$case tree where every node has one

null link, except one at the bottom, which has two null links. Give

five other orderings of these keys that produce worst$-$case trees.

You can also describe the constraints that produce this outcome

$---$ Things like "insert A first, insert B before C$,$ etc."