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Category Archives: Mathematics
“Venn diagram” partitioning
Paddy3118 wrote about partitioning elements in the same way a Venn diagram does. So, if we have sets A, B and C, the partitions are
Posted in algorithms, chatter
1 Comment
Adrift is NPcomplete
There’s a lovely new puzzle game for the iPhone called Adrift. I got it last week when I was in bed with flu, and it’s a fun way to spend a few hours. The puzzles look like this: And you … Continue reading
Posted in Mathematics
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John H Conway and the invention of the filing cabinet
Conway is incredibly untidy. The tables in his room at the Department of Pure Mathematics and Mathematical Statistics in Cambridge are heaped high with papers, books, unanswered letters, notes, models, charts, tables, diagrams, dead cups of coffee, and the most … Continue reading
Posted in chatter, Mathematics
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The Prisoner’s Dilemma
The Prisoners’ Dilemma The Prisoner’s Dilemma is a game, but a game that seems to bear lessons for the conduct of human affairs more generally, and it has attracted a great deal of attention from men not noted for their … Continue reading
Posted in chatter, Mathematics
23 Comments
On editing text
Editing text is the opposite of handling exceptions; or, to put it another way, editing text is like exception handling but backwards in time. I realise this is an unexpected claim, so I hope you will permit me to explain. … Continue reading
Posted in algorithms, category theory
17 Comments
Challenging the Power of Twitter
Most of the time I use this blog to write about things I understand, so it was something of an experiment when on Sunday evening I wrote a short post about something I did not understand.
Posted in chatter, Mathematics
2 Comments
Something I don’t understand about homomorphic encryption
Added later: In retrospect, now I know a little more about cryptography, I can see that my confusion here is caused entirely by the fact that I didn’t know the meaning of the technical term “semantic security”. Ever since Craig … Continue reading
Posted in algorithms, chatter
6 Comments
Computing Fibonacci numbers using Binet’s formula
A few months ago I wrote something about algorithms for computing Fibonacci numbers, which was discussed in some of the nerdier corners of the internet (and even, curiously, made it into print). Several people suggested that Binet’s closedform formula for … Continue reading
Counting small mazes
Before we get into general algorithms for counting mazes, I thought it would be interesting to do some small cases by hand. It’s quite fun to do, and it’ll give us a few numbers to check against the results of … Continue reading
Posted in mazes
3 Comments
Counting mazes: before we begin
If you’re following the maze series, I hope you’re persuaded that thinking about how to count mazes is a reasonable line of attack on the random access problem.
Posted in Mathematics, mazes
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