• Continue Partners!

Overview

• Preliminaries.
  • Admin.
  • Upcoming Work.
  • Extra Credit.
  • Questions.
• Quiz.
• Lab.

Preliminaries

Admin

• Welcome to our admitted student.
• Given where I found Corn Nuts, I may never bring food again.
• Review session Monday at 7pm.
• It's nearly prereg time. Think about taking 161 in the fall!
• A friendly reminder: If you miss class, you do have an obligation to send me a note.
• If you have three large things due next week (including the 151 exam), and you think some extra time would help, please let me know.
  
  • But remember that you'll be starting on the project!

Upcoming Work

• Lab writeup: Exercise 4c http://bit.ly/151-2015S-lab39
• Readings for Monday: Elements and Principles of Two-Dimensional Design and About the Project

Extra Credit Opportunities

Academic

• CS Extras next Thursday: Nora Bressette Buccino on her summer REU (Android and Robots!)
• CS Table next Friday: TBD.

Peer Support (Afternoon Section)

• Womens Tennis Sunday at 3pm against Central.
• ISO Show, Saturday night 7-9 pm at Harris. Many live performances.
• How an admitted student this coming Sunday night (or the following Sunday night)! Contact JMU for info.
• Psych Alum talks next Tuesday and Thursday, probably 4:15pm. Learn more on Monday.
• Contra Dance Workshop Thursday the 16th at 7:30 pm in BCA Dance Studio.
• Salsa Showcase Harris 7:30ish on Friday the 17th.
• More things to be announced next week!

Miscellaneous

• Town hall April 23, noon or 7:30 pm, "How we have conversations."

Other Good Things (no extra credit)

None

Questions on the exam

Can we copy turtle-line! directly into our exam code?

Yes! (You might even cite it, but you are not required to because it appears in the exam.)

Questions on other issues

Is (cons 'a 'b) the same as (list 'a 'b)?

No

Quiz

• If you finish before your partner, bring up DrRacket and the reading

Lab

Extra credit to the first person who can explain why I want to say "Rawhide!" during lab.

Multiple strategies for tally-seven-eleven (forthcoming)

• Use a let to name the roll

  (define tally-seven-eleven (lambda (n) (cond [(<= n 0) 0] [(let ([roll (pair-a-dice)]) (or (= roll 7) (= roll 11))) (+ 1 (tally-seven-eleven (- n 1)))] [else (tally-seven-eleven (- n 1))])))

• Use a let to name a procedure that checks whether a roll is 7 or eleven

  (define tally-seven-eleven (let ([seven-or-eleven? (lambda (val) (or (= val 7) (= val 11)))]) (lambda (n) (cond [(<= n 0) 0] [(seven-or-eleven? (pair-a-dice)) (+ 1 (tally-seven-eleven (- n 1)))] [else (tally-seven-eleven (- n 1))]))))

• Use member?

  (define tally-seven-eleven (lambda (n) (cond [(<= n 0) 0] [(member? (pair-a-dice) (list 7 11)) (+ 1 (tally-seven-eleven (- n 1)))] [else (tally-seven-eleven (- n 1))])))