# Tag Archives: algorithm

## A few words about PWW #20

A couple commenters quickly figured out what my previous post without words was about. The dots making up the image are at integer grid points , with the center at . There is a dot at if and only if … Continue reading

Posted in pattern, pictures, posts without words | Tagged , , | 10 Comments

## Post without words #20

Posted in pattern, pictures, posts without words | Tagged , , | 7 Comments

## A new way to read (and print) double-sided paper

Continuing with the theme of reading stacks of paper (see my previous two posts, I have had a marvellous idea (at least I think so; I will let you judge for yourself). Let me take you through my thought process, … Continue reading

Posted in pattern, solutions | Tagged , , , , , | 11 Comments

## Reading double- and triple-sided paper

In the comments on my previous post there are some nice suggested algorithms for reading a stack of double-sided sheets of paper. The key seems to be that you need to keep track of a distinguished edge of the stack. … Continue reading

Posted in Uncategorized | Tagged , , , , , , | 5 Comments

## John Conway’s algorithms for counting stairs and reading double-sided paper?

This past week I started reading Siobhan Roberts’s new biography of John Conway, Genius at Play: The Curious Mind of John Horton Conway. I’m enjoying it so far. I’ll have more to say about it later, once I finish it, … Continue reading

Posted in Uncategorized | Tagged , , , , , | 9 Comments

## The Steinhaus-Johnson-Trotter algorithm

In a previous post I posed the question: is there a way to list the permutations of in such a way that any two adjacent permutations are related by just a single swap of adjacent numbers? (Just for fun, let’s … Continue reading

Posted in combinatorics, pattern, solutions | Tagged , , , , , | 9 Comments

## The hyperbinary sequence and the Calkin-Wilf tree

And now, the amazing conclusion to this series of posts on Neil Calkin and Herbert Wilf’s paper, Recounting the Rationals, and the answers to all the questions about the hyperbinary sequence. Hold on to your hats! The Calkin-Wilf Tree First, … Continue reading