Ex-2.64

;a
Once again, this demonstrates the power of wishful thinking. (partial-tree elt n) assumes that a left-sub-tree with first (quotien (- n 1) 2) elements of elt and a right-sub-tree of last (- n (+ left-size 1)) elements of elt is available and then it just constructs the tree using left-sub-tree, right-sub-tree and this-entry(the middle entry thats not included in any of the sub-trees).

1 ]=> (list->tree '(1 3 5 7 9 11))
;Value 19: (5 (1 () (3 () ())) (9 (7 () ()) (11 () ())))

;b
t(n) = 2t(n/2), hence O(n)