Notes: Friday 5 March 2004

Schedule

• Now: Problem Set 5
• Before 15 March: Read the rest of GEB Part I (see Notes 5)
• Monday, 22 March: Problem Set 6

  The schedule for the rest of the semester has been revised:

• Problem Set 7 will be handed out on 22 March, and due on 2 April.
• Problem Set 8 will be handed out on 2 April, and due on 12 April (Part I) and 26 April (Final).
• Exam 2 will be handed out on 16 April and due on 19 April.

Quicksort

(define (quicksort cf lst)
  (if (null? lst) lst
      (append 
        (quicksort cf 
           (filter (lambda (el) (cf el (car lst))) 
                    (cdr lst)))
        (list (car lst))
        (quicksort cf 
            (filter (lambda (el) (not (cf el (car lst))))
                     (cdr lst))))))  

Sort these evaluations according to how much time they are likely to take:

1. (quicksort < (intsto 100))
2. (quicksort < (rand-int-list 100))
3. (quicksort < (reverse (intsto 100)))
4. (quicksort > (reverse (intsto 100)))
5. (tuttlesort < (intsto 100))
6. (tuttlesort < (rand-int-list 100))
7. (map (lambda (x) x) (intsto 100))
8. (map (lambda (x) (* x x) (intsto 100))
9. (quicksort < (apply append (map (lambda (n) (intsto n)) (intsto 100))))

GEB Study Guide

Your reading assignment for Spring Break is to finish reading the first part of Gödel, Escher, Bach (up through and including Chapter IX). The questions below might help you think about the reading. Then again, they might not. I am quite certain, however, that they will not help you prepare for the quiz that will not be given on March 15.

Answer all the answerable questions, but unask the unanswerable ones. This quiz will not be graded, but it won't be ungraded either.

1. If you knew the answer to this question, what would it be?

2. Does this question have no answer?

3. Is the next question trickier than this one?

4. Was the previous question fairer than this one?

5. If this exam were graded, would your answer to the previous question be different?

6. If this exam were graded, would your answer to the previous question be different?

6. If this exam were graded, would your answer to the previous question be different?

7. If you were Gödel, how would you answer this?

8. Richard Feynman once said "If you think you know how quantum mechanics works, you're wrong." If Feynman were a logician instead, would he have said "If you think you don't understand Gödel's Theorem, then you do." or "If you don't think you don't understand Gödel's Theorem, then you don't."?

9. If your final grade in CS200 depended only on your answer to this question, would your answer to this question be different?

10. Ask and answer the question should I have asked instead of this one.

Golden Ages Links

• Great Books of the Western World (How many were written in the last 15 years? When was the golden age of literature?)
• Steve Jobs: Personal computer enters 'third golden age'
• Golden Age of Jazz
• Two Golden Ages Masterpieces of Dutch and Danish Painting

• Grade inflation articles (relate them to Tyson's essay): Grade Inflation at Virginia Universities: Does A Stand for Average?, Virginia-Pilot, Sunday, 9 February 2003; Cavalier Daily, Making the Grade, 19 March 2003 (the Cavalier Daily also published a letter on this subject).
• Neil deGrasse Tyson: Speech delivered at the State Department to Presidential Awarded for Excellence in Mathematics and Science Teaching (elementary school teachers) (I am also the student whose 6th grade home-room teacher wrote, "Less social involvement and more academic diligence is in order".); Rose Center for Earth and Space.

  The progress of invention and discovery of improvement and application is so rapid,
  unceasing and continuous, that it would require a volume many times the size of the present,
  to record, even in a summary fashion, all that transpires of scientific interest in the course of a single year.

  David A. Wells, Annual of Scientific Discovery, 1852. (Quoted in Neil DeGrasse Tyson's essay.)