CS 61A, Spring 97
Midterm 1
Professor Harvey
Problem #1 (7 points):
What will Scheme print in response to the following expression? If an expression produces an error message
or runs forever without producing a result, you may just say "error"; you don't have to provide the exact text
of the message. If the value of an expression is a procedure, just say "procedure"; you don't have to show the
form in which Scheme prints procedures. Assume that no global variables have been defined before entering
these expressions, except where noted.
(se '(+ 2 3) (+ 2 3))
((lambda (x y z) (+ x 5)) 6 7)
; from ex. 1.32, p. 61
(accumulate se 0 (lambda (x) x) 3 (lambda (x) (+ x 1)) 5)
((if 3 - *) 23 2)
(a b c)
(let ((a 5) (b (+ a 3))) (* a a))
((lambda (f) (f f)) (lambda (f) f))
Problem #2 (2 points):
True or false?
A theta( nlog(n)) algorithm is, for all large enough n, slower than a theta ( n^2) one. _____
For small size inputs the theta order of an algorithm helps predict running time. _____
Function f below defines a linear iterative process:
(define (f a b c)
(if (> a b)
c
(f (+ a 1) (- b 1) (+ c 1)))) _____
Function g below defines a linear iterative process:
(define (g a b c)
(if (> a b)
c
(+ c (g (+ a 1) (- b 1) (+ c 1))))) ______
Problem #3 (10 points):
CS 61A
1
