You'll recall from week zero that one of the first problems we solved
was looking up someone in a phone book.
Well, here I have a pretty thick yellow pages wherein
there's a whole bunch of products and services alphabetized from A to Z.
And we can, of course, look up the number for someone in this book.
For instance, suppose today we need a plumber.
Could we ask Mariano to find us a plumber in this phone book?
Flipping through a few pages.
A lot of pages.
Yeah.
OK.
All right.
And we have a page full of plumbers.
And now, could your dad have done better do you think?
DANIELLA: Yes.
DAVID MALAN: I think so.
So would you like to show dad and other parents here
what you might have done instead?
Oh my goodness.
[LAUGHTER]
OK.
Thank you.
[APPLAUSE]
[LAUGHTER]
DAVID MALAN: And for those wondering, let's continue the algorithm,
if you will.
What's your next step?
[LAUGHTER]
Nice.
And why are you doing this, though?
DANIELLA: So I open halfway and then if it's not on the page
and it looks like, for example, if it's n, I know p is afterwards.
So I need to get rid of the first half and just look at the second half.
DAVID MALAN: Well, need to is a little strong.
[LAUGHTER]
But you can get rid of--
yes, indeed.
So if you keep this process going, halving, and halving, and halving,
what should you be left with ultimately?
DANIELLA: Just the letter p.
DAVID MALAN: Just the letter p.
Round of applause would be good for both of our volunteers here.
[APPLAUSE]
DAVID MALAN: Thank you.