Skip to Content
Puzzles for Programmers and Pros
book

Puzzles for Programmers and Pros

by Dennis E. Shasha
May 2007
Intermediate to advanced
240 pages
5h 20m
English
Wrox
Content preview from Puzzles for Programmers and Pros

1.5. Reach for the Sky!

Reach for the Sky! is based on hollow lottery balls. Here is how it is played.

Your adversary is given 100 identical pieces of paper. In a room hidden from your view, he writes a number on each one—he can choose any value in the range 1 to 1 million but without duplicates—then inserts them into small opaque envelopes. Subsequently, these papers are given to an independent third party called the "stuffer." The stuffer works in full view of you and your adversary at all times. He shows you 100 hollow and empty lottery balls. He then shuffles the envelopes and inserts one envelope into the first lottery ball, another into the second, and so on up to 100. After inserting each envelope, he screws the ball shut. These balls have been examined using drop tests, bounce tests, and resiliometric tests to be sure they all share the same physical properties.

The stuffer then puts the balls into a lottery machine. The lottery machine mixes the balls thoroughly until one comes out. Call that ball number 1. The ball is opened and you are told the value on the paper (what we will call the 'paper value' for short). You have the option to 'capture' that paper value or not. If you capture it, you put it in your capture pile and you have used up one capture. If you don't, it goes in the discard pile never to come out, though you may find it useful to remember the discarded paper values. Repeat this procedure for all 100 balls. You are allowed three 'captures' altogether. Your ...

Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.

Read now

Unlock full access

More than 5,000 organizations count on O’Reilly

AirBnbBlueOriginElectronic ArtsHomeDepotNasdaqRakutenTata Consultancy Services

QuotationMarkO’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.
Julian F.
Head of Cybersecurity
QuotationMarkI wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.
Addison B.
Field Engineer
QuotationMarkI’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.
Amir M.
Data Platform Tech Lead
QuotationMarkI'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
Mark W.
Embedded Software Engineer

You might also like

Mazes for Programmers

Mazes for Programmers

Jamis Buck

Publisher Resources

ISBN: 9780470121689Purchase book