Starting from an empty binary search tree, create a binary search tree with the

numbers: $6,8,3,4,5,9,11,2$

a$.$ What keys would be examined when in a search for $4?$

b$.$ What keys would be examined when in a search for $7?$

$2.$ Starting from an empty binary search tree, create a binary search tree with the letters:

M$,$ E$,$ M$,$ P$,$ H$,$ I, S

Use alphabetical $($or ASCII$)$ ordering to determine if how a letter compares to another.

a$.$ What keys would be examined when in a search for H$?$

b$.$ What keys would be examined when in a search for R$?$

$3.$ Which of the above are valid binary search trees?

$4.$ Label each of the above as a full, perfect, or complete binary tree.

a$.$

b$.$

c$.$

d$.$