a$)$ In an empty binary search tree, insert the following letters in this order: q w

e r t z u i

b$)$In an empty $2-3-4$ tree, insert the following letters in this order: q w e r t z

u a d u f x y z

Use top$-$down insertion. Redraw the $2-3-4$ tree each time you change the structure

and delete the r symbol after you have inserted everything.

now do the same but for bottom up insertion