Eboard 16 (Section 2): Searching

You are probably being recorded (and transcribed)

Approximate overview

• Preliminaries
  • Notes and news
  • Upcoming work
  • Tokens
• Questions
• Lab

Preliminaries

News / Notes / Etc.

• Welcome back from break!
• Grab an official class pen.
• It’s good to be back in the class.
• I’m struggling to catch up on everything, but I’m trying. Please DM me with questions.
• I’ll do reading responses for today’s class on Thursday, including a discussion of invariants.

Upcoming work

• TODAY: Tuesday, 2024-10-29
  • Consider submitting Writeup from lab 16: Searching
• Wednesday, 2024-10-30
  • Submit Writeup from lab 16: Searching
  • Read Sorting basics
  • Submit Reading responses for class 17
• Thursday, 2024-10-31
  • No lab! It’s a talk day.
  • Mini-project 7 assigned.
• Sunday, 2024-11-03
  • Submit pre-reflection for MP7
• Monday, 2024-11-04
  • Some random readings.
• Tuesday, 2024-11-05
  • SoLA 7 (forthcoming)

Tokens

If you’d like to suggest token events, please let me know in advance of class.

Academic/Scholarly

• Thursday, 2024-10-31, 4:00–5:00 p.m., Science 3821. CS Extras: Data Science
• Sunday, 2024-11-03, 7:00–8:00 p.m., Science 3819. Mentor Session
• Tuesday, 2024-11-05, Noon–1:00 p.m., JRC 224A (Day PDR). CS Table

Cultural

• Friday, 2024-11-01, 7:30–9:00 p.m., Sebring-Lewis. The Infinite Wrench.

Multicultural

• Friday, 2024-11-01, 4:00-6:00 p.m., HSSC N1170 - Global Living Room. Middle of Everywhere: Day of the Dead
• Friday, 2024-11-08, 4:00-5:00 p.m., HSSC N1170 - Global Living Room. Middle of Everywhere

Peer

Wellness

• Friday, 2024-11-01, Noon–1:00 p.m., BRAC P103 - Multipurpose Dance Studio. Yoga.
• Tuesday, 2024-11-05, 4:00–5:00 p.m., HSSC S1003 - Atrium. Therapy Dogs.
• Tuesday, 2024-11-05, 4:30–6:30 p.m., BRAC P103 - Multipurpose Dance Studio. Wellness Yoga.
• Tuesday, 2024-11-05, 4:30–6:30 p.m., Secret Place. Forest Bathing.

Misc

Other good things (no tokens)

Questions

Administrative

What did it mean that SoLA 6 was optional?

It meant that you didn’t have to do it.

But I don’t have to do any SoLAs!

It was a bit more optional than most.

Will the new questions on SoLA 6 appear on other SoLAs?

Yes. You can pretend that they are new for SoLA 7. There will also be a few other new ones for SoLA 7. (We need about 5–6 new LAs per SoLA.)

I’m almost out of token space. Will you add more?

Yes. I guess I should read those.

Do therapy dogs count for tokens?

Yes. But I prefer if you remind me so that they get on the list (so that I can remind others).

Probably Nov. 5.

Do yoga and forest bathing count for tokens?

Yes. But I prefer if you remind me so that they get on the list (so that I can remind others).

Readings

Miscellaneous

Lab

The person closer to the board is Driver A. The person further from the board is Driver B.

Make sure that the name of the repo ends with -maven.

Questions

How should we find the midpoint of the region given by lb and ub?

Most people use (lb + ub) / 2.

I tend to prefer lb + (ub - lb) / 2.

You could also use lb / 2 + ub / 2 + ..., where the ellipses handle the issue that both might be odd. This one is probably safest.

If we’re writing the recursive binary search, can we write a helper?

Of course. That’s why we provided a template for one.

Oh no! It’s storytime with Sam!

• On writing a correct binary search: Even professional programmers get it wrong.
• On testing binary search: There are weird points where binary search goes wrong; we’re not good at thinking of them. We should write a comprehensive test.
• On computing the midpoint: Even “correct” code can be incorrect if you don’t pay attention to all the details.
• On bounds: It’s good practice to do lb inclusive and ub exclusive. Then when you do recursion, you can write recurse(lb, mid) combined with recurse(mid, ub).