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Programming Enigma Puzzles

4 April 2013

Posted by on There is now a continuous span of 300 *Enigma* puzzles starting from **Enigma 1445** (June 2007) to the most recently published puzzle, **Enigma 1743** (April 2013) on the site. So I thought it would be nice to have a little analysis.

By my own subjective measure there have been 21 “**Notable Enigmas**” during that period (for me a “Notable Enigma” is one that involves a significant and enjoyable programming challenge).

Here’s the interval between those Notable Enigmas, plotted as a bar chart. (Note that the top bar is not an interval between Notable Enigmas, rather the period since the last one).

On average there is a Notable Enigma every 14.3 puzzles [*], but they are not evenly distributed. For instance, when I started the Enigmatic Code site (November 2011), we’d recently had two Notable Enigmas quite close together (**Enigma 1661** and **Enigma 1669**), but before that we’d had a “drought” lasting for 51 puzzles (there are 51 editions of **New Scientist** published per year), and before that **Enigma 1589** broke the longest recorded drought of 53 puzzles.

Looking back I had in mind the pleasant era between **Enigma 1491** (April 2008) and **Enigma 1520** (November 2008) when I set up the site. In that period we never had to wait longer than 8 weeks for a challenging programming puzzle to come along.

We are currently in the third longest recorded “drought”. There have been 32 puzzles published since **Enigma 1712** (August 2012). But that’s not to say some recent puzzles haven’t been interesting – just not much of a programming challenge. For instance:

**Enigma 1715**(September 2012) generated some interesting discussion.**Enigma 1718**(October 2012) contained some interesting analysis.**Enigma 1719**(October 2012) led to some interesting variations on algorithms.**Enigma 1732**(January 2013) got me reading up about Harmonic Series.**Enigma 1739**(March 2013) got me looking at Pell’s Equation, Continued Fractions and their use in computing square roots.

I hope we soon end the drought have a new addition to the Notable Enigmas at the top of the list, but in the meantime I’m sure I shall continue to unearth gems hidden in the back catalogue of Enigma puzzles. Or I shall have to become less picky!

—

[*] There are also an additional 78 Enigma puzzles on this site from 1979 and 1980, when the puzzle was in its infancy. These have contributed 7 Notable Enigmas over 70 puzzles, so at the beginning Enigma had a faster rate, with Notable Enigmas turning up every 10 puzzles.

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As a new comer to Enigmas my choices of the last 25 Enigmas were:

1725-arithmetic progression including sum of squares

1726-velocity-travel

1728-tackling-speed

1731-power game

I am a paper and pencil puzzle solver and value the Enigmas accordingly at a rate of an Enigma a week which I hope to increase this speed of mine a bit faster thanks to your valuable effort to cover almost all the past Enigmas.