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Can You Do the Regular Expression Crossword?

Posted by samzenpus on from the game-time dept.

mikejuk writes "Programmers often say that regular expressions are fun ... but now they can be a whole lot of fun in a completely new way. Want to try your hand at a regular expression crossword? The idea is simple enough — create a crossword style puzzle with regular expressions are the 'clues.' In case you don't know what a regular expression is — it is a way of specifying what characters are allowed using wild-card characters and more. For example a dot matches any single character, an * any number of characters and so on. The regular expression crossword is more a sort of Sudoku puzzle than crossword however because the clues determine the pattern that the entries in a row have to satisfy. It also has to use a hexagonal grid to provide three regular expressions to control each entry. This particular regular expression crossword(pdf) was part of this year's MIT Mystery Hunt. This annual event is crammed with a collection of very difficult problems and the regular expression crossword, created by Dan Gulotta from an idea by Palmer Mebane, was just a small part of the whole — and yes there is a solution."

5 of 115 comments (clear)

  1. Great idea, but... by stephanruby · · Score: 3, Insightful

    It's a great idea, but the puzzle given is too complicated.

    If they really want to popularize this concept among programmers, many of whom have forgotten regular expressions even if they had once mastered them, they should really create much simpler puzzles in a mounting order of difficulty.

    Hopefully, someone enthused by the idea will create and publish such puzzles.

    1. Re:Great idea, but... by Anonymous Coward · · Score: 1, Insightful

      I don't know a single programmer who has forgotten regular expressions. Who are the "many" you speak of?

      Besides, rather than the puzzle being too complicated, maybe your brain is too simple?

    2. Re:Great idea, but... by Anonymous Coward · · Score: 2, Insightful

      Really? I'm about as far from a Regex Guru as you can get and frequently advocate against using them for anything but the simplest task and I was able to solve it in about 45 minutes or so. When you first sit down with it, it looks near impossible, but there are a handful of hexes that can be deduced immediately and after getting a few more it's not that much harder than a sudoku.
      I though the puzzle was challenging, but not overwhelmingly so in any way and would love to see more of them.

  2. Re:Rules? by Anonymous Coward · · Score: 2, Insightful

    The rules are anchored to the ends. Printing a ^ and $ on each clue is redundant and silly, when a moderately intelligent person could easily figure that part out for themselves.

  3. Re:Obligatory xkcd by fche · · Score: 5, Insightful

    Randall should draw a comic about obligatory xkcd references.