Overview

• Preliminaries.
  • Admin.
  • Upcoming Work.
  • Extra Credit.
  • Questions.
• Some time to work on Friday's lab
• Lab

Preliminaries

Admin

• Quiz! (For those who did not take the quiz on Friday.)
• Continue partners (since I said you could continue Friday's lab)
• I will continue to bring you food (or food-like substances) until I am caught up on grading.
• You will need at least one sheet of paper today. Grab one from the back of the room.
• I have not had the opportunity to read much email today. If you sent a question, I'll get to it early this evening.
• We'll have a little time at the start of class for you to work on Friday's lab. (Please start on today's lab at 3:25 p.m.)

Reminders

• Office hours this week
  • See http://rebelsky.youcanbook.me.
  • Ask me about other available times.
• Tutor hours
  • Sunday, 3-5 p.m.
  • Sunday-Thursday, 7-10 p.m.
• Review Sessions
  • Wednesday at 8pm in CS commons with Sarah
  • Thursday at 8pm in CS commons with Kumar
  • None with Sam this week

Upcoming Work:

• Reading for Tuesday:
  • Reading: Vectors
• Lab Writeup: Exercise 3
  • Hand me a piece of paper (one per group) with the answers and your names.
  • Due before class on Wednesday.

Extra Credit

• Send your reports to rebelsky@grinnell.edu with subject "CSC 151 Extra Credit". (Do not include the quotation marks.)
• Send opportunities to me before class with subject "CSC 151 EXTRA CREDIT OPPORTUNITY!"

Academic / Artistic

• Talk today, 4pm, ARH 302
• Talk Wednesday, 4pm, ARH 302
• Talk Thursday, 4pm, place TBD
• Any of the fora on "Thrive Not Survive" this or next week.
• Student research symposium (lots of options)
• Concert Saturday Grinnell Symphony Orchestra and a Cowboy Singer

Peer

• Lords of the Flies, 7:30 pm April 22nd, 2:00 pm April 23rd, 2:00 9pm April 24th. Roberts on sale next week. (Only 50-60 tickets per show)
• Bollywood "Bhangra" Dance in ISO, Saturday, April 16, 7-9pm (probably the first half of the show) (other peers, too)
• No Second Annual Contra into Spring Dance, April 22nd, Main Quad, 7:30
• Asian American Association event TODAY at 4:30 in Mears; being a person of color in a creative discipline

Miscellaneous

• Host a prospective student this coming weekend.

Regular Peer

• Social Dance Workshop Tuesdays 7:00-8:00 in Bucksbaum Dance Studio
• Post-break ExCo on British Politics Wednesdays at 8:00 in JRC 203.
  Just show up; you don't need to sign up.
• Pun club Saturdays at 4pm in Younker
• Electronic Potpourri on KDIC Fridays at Five
• Space Odyssey KDIC Fridays at Six
• Bollywood, Fridays, 7:30-8:30, Younker
• Effective Altruism club, 2:30-3:30 Sundays in JRC 226.

Misc

Far in the Future

• Adaptation of Rushdie's East West. Early May.

Questions

I'm having trouble with postconditions for rac and rcd.

For rdc, you can talk about the length of the list and the value at each position.

For rac, you can probably rely on list-ref to clarify the
postcondition.

Can we use position-distance in solving the stenciled circle problem?

Yes.

Can we text you with questions tonight?

Yes. But before 10 p.m. (You can email after 10 p.m.; the odds are that I'll still be awake.)

Are there positive aspects to your failure to grade exam 2 in a timely fashion?

Yes. I am much less likely to take off for formatting and insufficient examples on exam 3.

What should index-of-substring return if there are multiple matching positions?

Any of those positions (usually the first).

Any hints on finding the errors?

Be thorough. If it were me, I'd try more substring sizes and more substring positions. And think about edge cases.

Is banana a subtring of banana?

Yes.

What is (rac (list 5))?

5

What is (rdc (list 5))?

null or '()

What do I use as the type for a list that can contain any type of value?

"list" or "heterogeneous list"

I have this fantasy that you give partial credit. How do you determine how much partial credit we receive? In particular, should I transcribe my scratch paper?

No work implies no partial credit.

Seeing your work helps me give partial credit. (Put in comments about your thought process, and commented out failed attempts with notes about what you learned.)

I forgot about the letter between O and Q during break. For "Produces", what do I give?

Typically, the name and the type. You explain further in the postconditions.

Can strings and substrings have spaces?

Yes. Good thinking about edge cases.

Randomness Lab, Revisited

Writeup: 1b

Pairs Lab

Writeup: Exercise 3