### HORIZONS IN COMPUTER SCIENCE EDUCATIONAL TECHNOLOGY

By Ross Williams 3 June 1988.

Recent studies have shown that while undergraduate students are more intelligent than kindergarten students, the mentality and attention span of the two groups are similar. With this in mind, we introduce a new concept in Computer Science education:

### COMPUTER SCIENCE SESAME STREET

Narrator:
One of these programs is not like the others,
One of these programs has a bug.
One of these programs is not like the others,
And if you can't tell which one, you're a mug.

One of these programs is not like the others,
One of these programs will really teach yer,
One of these programs is not like the others,
Yes, that's not a bug, that's a feature.

Voiceover:
c
C
C?
C!
printf!
while ((c=getchar() != EOF) {}
C!

Song:
Dum diddle diddle diddle dum de dum dum, Dum diddle diddle diddle,

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A
B
C
D
E
F

Narrator: Hello Oscar, how are you today?

Oscar the Grouch: Go away: I've just found a new garbage collection algorithm.

Narrator: Tell me about it Oscar....

Kermit: This is Kermit the Frog reporting for Sesame Street news. Today, we interview Professor Biskit who works on cookie biosearch. Hello Professor Biskit, what have you got there?

Prof: Arcchhh, I am trying to find out iv there is zarch a sing as an infinitely long coorkie. Dis machine vill produce every sort of coorkie possible: big cookies, dittle cookies, square cookies, round cookies. The cookies come out dis hole here.

Kermit: You mean if you get a really long cookie, it will come out of the hole like a sausage?

Prof: Yaaaass, that's right. Now I vill set de machine going, and ve can start vatching de corkies.

GRRRRUNNNCCHHHH CHUGGA CHUGGA CHUGGA CHUGGA...

Prof: Aass here comes one,... CLUNK

Prof: Und another. Dis one eees square: CLUNK.

Kermit: Uh professor...

Prof: Don't bother me now, I'm vatchin coorkies.

Kermit: What if there isn't an infinitely long cookie?

Prof: Then they vill come out of dis machine forever - there are an infinite number of possible corkies you know.

Kermit: And what if the machine starts making an infinitely long cookie?

Prof: Thats obvious you frogk, I vill have to vait for it to come out.

Kermit: And how long will that take?

Prof: Forever.

Kermit: So if there isn't an infinitely long cookie, you have to wait forever and if there is, you have to wait forever too. How are you going to find out if there is an infinitely long cookie today?

Prof: Don't interrupt. Here comes a triangular one viff purple spots.

Prof: My machine!

Kermit: Well, it looks as if the cookie monster has transcended the question of whether there is an infinitely long cookie by eating the cookie machine. A good thing as the computation was UNCOMPUTABLE.

Narrator: Hello Big Bird. What's all this mess?

Big Bird: I'm planting a binary tree. That way, I can nest in it and I won't have to fly South for the winter.

Narrator: How long will it take for the tree to grow tall enough?

Big Bird: If I add branches randomly it will take me log_2(t)/1.386.

Narrator: Tell me why, Big Bird?

This program has been brought to you by the language C and the number F.
This has been a production of the Computer Science Television Workshop.

### COMPUTER SCIENCE YOUNG ONES

Neil: Ow, WOW heavy! My lentil binary trees are growing exponentially.

Vivian: This calls for a subtle combination of mathematics and extreme violence.

Rick: Oh you couldn't theorize even if you picked your nose with a silicon chip.

Vivian: OK, watch! This is how you dismantle a binary tree in constant time...

CRUNCH, CHOP, CRASH...

Neil: WOW. Heavy. Look at the mess. Look at all the garbage!

Garbage: Now they'll try to clean me up in constant time, but they've forgotten about all those cycles caused by curly lentils...

Vivian: Oh no we didn't because I cut all the cycles before I chopped down the tree...

Rick: You can't do that in linear time! What sort of a snotty nosed gullible girlie do you think I am?

Vivian: Well I had him fooled!

Neil: No you didn't! I was just waiting for the tree to spontaneously re-assemble.