EBoard 34: Trees (Section 2)
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Approximate optimistic overview
- Administrative stuff
- Questions!
- Lab
Administrative stuff
Introductory notes
- Welcome to our prospective/admitted students! Please introduce
yourself and ask a question. “Grinnellians ask hard questions and
question easy answers”, or at least that’s what our marketing
people used to say.
- I’ll be guest teaching classes next Tuesday, so office hours will only
be 8:30–9:45.
- As always, if you’d like to meet to me outside of office hours, let
me know.
- We are three people short on the mentor/tutor evals. If you haven’t
evaluated yet, please do so.
- I’ll be sending out notes on the quizzes tonight or tomorrow.
Upcoming activities
Scholarly
- Tuesday, 29 April 2025, noon–1pm, White PDR.
CS Table: ???
- Thursday, 1 May 2025, 11:00 a.m.–noon, JRC 101.
Dr. Tammy Kernodle: My Song is My Weapon: Women, Social Movements,
and the act of Freedom Singing
Artistic
- Any day it’s open. GCMoA.
BAX
- Saturday, 26 April 2025, 1:30–3:00 p.m., Bucksbaum Rotunda.
Shadow Puppet Workshop
- Saturday, 26 April 2025, 2:00–3:00 p.m., Herrick.
Young, Gifted, and Black Gospel Choir
- Saturday, 26 April 2025, 2:00–4:00 p.m., Sebring-Lewis.
Orchestra
- Saturday, 26 April 2025, 7:00–8:00 p.m., Sebring-Lewis.
Elliot Swaim Voice Recital
- Saturday, 26 April 2025, 7:30–8:30 p.m., Flanagan.
Dance Ensemble/ACTivate: A Rebours
- Sunday, 27 April 2025, 2:00–3:00 p.m., Flanagan.
Dance Ensemble/ACTivate: A Rebours
- Sunday, 27 April 2025, 4:00–5:15 p.m., Sebring-Lewis.
Vox Feminae: Landlocked
- Tuesday, 29 April 2025, 4:00–5:00 p.m., GCMoA.
BAX Gallery Talk
- Tuesday, 29 April 2025, 7:00–8:00 p.m., Herrick.
Jazz Ensemble
- Note that the poster has the wrong date.
- Friday, 2 May 2025, 7:30–8:30 p.m., Flanagan.
Dance Ensemble/ACTivate: A Rebours
- Saturday, 3 May 2025, 2:00–3:00 p.m., Flanagan.
Dance Ensemble/ACTivate: A Rebours
Multicultural
- Friday, 25 April 2025, 4:00–5:00 p.m., HSSC N1170 (Global Living Room).
Middle of Everywhere: Spain
- Sunday, 27 April 2025, 1:00–8:30 p.m., Cleveland Beach. (Estimates.)
Holi
- Friday, 2 May 2025, 4:00–5:00 p.m., HSSC N1170 (Global Living Room).
Middle of Everywhere: ???
Peer
Musical, theatric, sporting, and academic events involving this section’s
students are welcome.
- Read articles by your fellow CSC-151 students and comment on them online.
- Saturday, 25 April 2025, Noon, Baseball field.
Baseball vs. Ripon
- Saturday, 25 April 2025, 2:30 p.m., Baseball field.
Baseball vs. Ripon
- Sunday, 26 April 2025, Noon, Baseball field.
Baseball vs. Ripon
Wellness
- When and where they usually occur.
Badminton Club, Brazilian Jiu-Jitsu, _HIIT Training,
Nerf at Noyce, Yoga.
- Saturday, 26 April 2025, 9:30 a.m.–12:30 p.m. CERA (leaves from JRC).
Woodland Wildflower Walk
- Tuesday, 29 April 2025, 5:00–6:00 p.m., HSSC Atrium.
Therapy Dogs.
- Tuesday, 29 April 2025, 7:15–8:15 p.m., HSSC Atrium.
Therapy Dogs.
- Tuesday, 29 April 2025, 7:00–8:30 p.m., Harris Concert Hall.
Queer Stompede.
- Thursday, 1 May 2025. 4:30–6:30 p.m., Off Campus.
Forest Bathing.
Misc
- Saturday, 26 April 2025, 11:00 a.m.–6:00 p.m., Mac Field.
DAG Field Day
- Sunday, 27 April 2025, 7:30–8:30 p.m., Science 3819.
Mentor Session: Quizzes and MPs
- Tuesday, 29 April 2025, 7:00–8:00 p.m., Science 3820.
Mentor Session: Quizzes
- Wednesday, 30 April 2025, Noon–1:00 p.m., HSSC A2231 (Auditorium)
Community Forum
- “Weekly discussion on legal protections and recourse on issues
that higher education and Grinnell College face.”
- Also online.
- This week: ???
Other good things
These do not earn tokens, but are worth your consideration.
Upcoming work
- Friday, 25 April 2025
- Sunday, 27 April 2025
- Tuesday, 29 April 2025
- [Submit Monday’s lab on Gradescope]
- No reading!
- Wednesday, 30 April 2025
- Our last quiz day!
- Quiz: Higher-order programming
- Makeup quiz: Data abstraction
- Makeup quiz: Diagramming structures (paper only)
- Don’t forget that you can bring a page of hand-written notes for
each quiz.
- Sunday, 4 May 2025
- Submit first redo for MP7 on Gradescope
- Friday, 9 May 2025
- Friday, 16 May 2025
- Submit final redo for MP1 on Gradescope
- Submit final redo for MP2 on Gradescope
- Submit final redo for MP3 on Gradescope
- Submit final redo for MP4 on Gradescope
- Submit final redo for MP5 on Gradescope
Friday PSA
- You are awesome. People care about you. Please take care of yourself.
- Get some rest / do something for yourself.
- Moderation is important!
- Consent is essential and insufficient.
Questions
Administrative
Project
How much time should we log for Wednesday?
30 minutes.
Should we all log that thirty minutes?
Yes.
Trees
Why do we use null for the first child if the node only has one
child, as opposed to using it for the second child?
We can use the empty tree for either child if it has only one
child; it depends on how we want to arrange the tree.
Why is Data Analyst under head of marketing if Data Analyst comes
first in the nested list? Shouldn’t be under “Head of Engineering”?
Because the person who drew the picture screwed up and I didn’t notice.
Why is the default a binary tree and not more elements?
That’s a great question. I suppose there are a variety of reasons.
A binary tree is the simplest “interesting” tree (unary trees are
just lists). We can also simulate any n-ary tree with a binary tree.
What does match refer to?
Damn! I thought I’d gotten rid of that. match is a procedure that’s in Scamper but we don’t use in our section of 151.
What is the point of binary trees? Is it just an easier way of
visualizing list within lists?
We don’t have to represent binary trees as nested lists. We could,
for example, use structs. In general, they end up being a useful
way to represent some kinds of information (as we’ll see next class).
How can we apply this idea of binary trees into coding to solve problems?
It’s mostly a way to think about how we organize information. As we noted,
there are hierarchical structures that occur in many situations. In addition,
as we’ll see next class, trees can let you organize information to
improve how we address some algorithmic problems, like searching.
Lab