Might I call on, say, two volunteers to
kick us off with two, say, algorithms?
Let's see.
Over here?
Yeah.
And let's go over here
in front, if we may.
Come on up.
And what are your names?
AUDIENCE: [? Nizari. ?]
SPEAKER 1: Lizari?
AUDIENCE: [? Nizari. ?]
SPEAKER 1: [? Nizari. ?] OK, David.
Nice to meet you.
Come on up, [? Nizari. ?] And
over here, what's your name?
AUDIENCE: Eric.
SPEAKER 1: Eric, OK.
David.
And come on up, Brian, as well.
Nice to meet you, Eric.
Eric, [? Nizari. ?] [? Nizari, ?] Eric.
[APPLAUSE]
Come on over here.
So you came on up the stage first.
Would you like to go first or go second?
AUDIENCE: I'll go second.
SPEAKER 1: You're going to go second.
So Eric, you're up first.
Come on over here, if you would.
So Eric, behind these seven doors we
have placed, in advance, the number 50.
And we would simply
like you, the computer,
to search this array for the number 50.
AUDIENCE: Is it sorted?
SPEAKER 1: I cannot answer
that question at this time.
Go.
Oh, and so that the
audience knows what's
going on, if you wouldn't mind
taking the numbers out to see.
AUDIENCE: This is seven.
SPEAKER 1: Excellent.
Not 50.
AUDIENCE: Should I-- can I take it out?
SPEAKER 1: At this point, yes,
you may do whatever you want now.
Just find us 50.
AUDIENCE: Two.
[LAUGHTER]
SPEAKER 1: Very good.
AUDIENCE: One.
SPEAKER 1: Nice.
AUDIENCE: Six.
SPEAKER 1: Very good.
AUDIENCE: Three.
SPEAKER 1: Nice.
AUDIENCE: None of these are close to 50.
SPEAKER 1: No, none of
them are close to 50.
AUDIENCE: Four.
SPEAKER 1: Four?
And?
AUDIENCE: 50!
SPEAKER 1: Amazing!
Very well done.
[APPLAUSE]
Very well done.
Now, if I may, Eric,
what was the algorithm
via which you found us the number 50?
AUDIENCE: Linear search.
SPEAKER 1: OK, linear
search, meaning what to you?
AUDIENCE: You just go in a line,
starting from there until there.
SPEAKER 1: OK, that was a
very sophisticated answer
to a term we've not yet introduced.
And that's great, linear search
from left to right, so literally
following a line.
And was your algorithm
correct, would you say?
AUDIENCE: Yes.
SPEAKER 1: OK, so it was correct.
But there's these different
parameters that we
want to optimize solutions for
not just correctness, but what
other property as well?
AUDIENCE: Design.
SPEAKER 1: So maybe design,
right, the efficiency.
So was that the most
efficient you could have done?
AUDIENCE: Actually, yeah, I think so.
[LAUGHTER]
SPEAKER 1: And why do you say that?
AUDIENCE: Because-- so
the numbers are sorted.
So at the end of the day, I have
to look through every single one.
SPEAKER 1: Yeah.
AUDIENCE: And it's just by
chance that the 50 was at last.
SPEAKER 1: Exactly.
So it's unfortunate that
they were all random.
And I didn't want to tell you because I
didn't want to bias your algorithm one
way or the other.
But not knowing if they're sorted
and them not even being sorted
means that that is the best you
can do, look at all of the doors
to find the number in question.
And maybe you could have gotten
lucky, if we had put 50 here.
But in the worst case,
Eric was, of course,
going to have to do exactly
that, searching all of the boxes.
So thank you, Eric.
Stay on stage with us, if
you would, for a moment.
And a round of applause, if we
could, for finding 50 so well.
[APPLAUSE]
[? Nizari, ?] could you come on up?
We need you not to look at
the numbers, because Brian
needs to do a little bit of magic.
And he's going to put some of
the numbers back into the locker.
So literally everyone in
the room will know what's
going on except you, at the moment.
But we're going to give you
the added bonus this time
of sorting the numbers in advance.
So Brian is in the process of
sorting some numbers for us.
The goal at hand, in
just a moment, is still
going to be the find the number 50.
I'm really just stalling right
now because he's still doing this.
So I don't really have anything
interesting to say just yet.
Brian's back now.
Hold on.
And would you like to
introduce yourself maybe?
AUDIENCE: I'm [? Nizari. ?]
SPEAKER 1: [? Nizari, ?]
and what year are you?
AUDIENCE: I'm a high
school student, a senior.
SPEAKER 1: Wonderful.
At what school?
AUDIENCE: Cambridge Rindge and
Latin, it's down the street.
SPEAKER 1: Just down the road.
So glad you can join us here today.
And perfect timing, if I may.
Now we have seven
lockers here behind you.
And the goal now is to
still find the number 50.
But I'm going to tell you
that the numbers are sorted.
So what's going to be your
algorithm, if not the same as Eric?
AUDIENCE: I will start--
SPEAKER 1: And here you go.
AUDIENCE: I'm going to
start in the middle.
SPEAKER 1: All right, go ahead
and show us what's in the middle.
AUDIENCE: Middle number is seven.
SPEAKER 1: All right.
And now what's your
next step going to be?
AUDIENCE: So I want to get to 50.
So assuming that they're sorted,
I'm going to go this way.
SPEAKER 1: Go to the right, OK.
So we have three lockers
remaining on the right-hand side.
What's your instinct now?
AUDIENCE: Mm, I'm going
to start with this locker.
SPEAKER 1: OK, this one being
in the middle of those three.
And you find?
AUDIENCE: And we got 81.
SPEAKER 1: 81.
AUDIENCE: So I know that's too big.
SPEAKER 1: Way too far.
AUDIENCE: Hoo, so I'm
going to go with this one.
SPEAKER 1: Which is now in
the middle of the two lockers.
AUDIENCE: And I got 50.
SPEAKER 1: And a round of applause,
if we could, for [? Nizari. ?]
[APPLAUSE]
Congratulations and
thank you to you both.
So thanks to you both.
