Wednesday, April 1, 2015

March 2015 1HaskellADay Problems and Solutions

March 2015
  • March 31st, 2015: Today's #haskell exercise has us looking for a really big pandigital prime ... like: REALLY big. Maybe.
  • March 30th, 2015: A little math-problem to ease us into the week, suggested by @jamestanton 3 consecutive integers that are co-composed
  • March 27th, 2015: Today's #haskell problem is unification of multiple free variables We find this to be 'CoSimple.' 34 lines (and a new n-to-1 data mapping-type) defining not a 'CoSimple' unifier but now an 'UnSimple' one. Ugh!
  • March 26th, 2015: Unification is interesting! (Functional Unification paper) Let's look at the unification-problem for today's #haskell problem We define simple unification (of up to one free logic variable) in a module called unification.simple, oddly enough.
  • March 25th, 2015: In Old Norse, words end with 'R' (not all). For today's #Haskell problem, relations end with 'R'
  • March 24th, 2015: For today's #haskell problem we learn that 'kayso' is a word, and we edge a bit more toward pure relational calculus A solution to this relational-calculus problem that is defined over Data/Control logic modules:
  • March 23rd, 2015: WHO KNEW a chance meeting with @webyrd at the POPL06 would lead to today's #haskell problem? μBikini I mean: μKanren And the solution implies that monadic-list states are logic programming? Perhaps.
  • March 19th, 2015: We now learn signal spreads ... like ... margarine! for today's #haskell problem
  • March 18th, 2015: For today's #haskell problem we learn that Jupiter's moon Europa is made from Froyo, and custard! Mmmm!
  • March 17th, 2015: No quaternions were harmed in today's #haskell π-problem IN SPACE!
  • March 16th, 2105: In space, no one can here you scream "@NASA" (nor anything else for that matter. Today's #haskell problem
  • March 14th, 2015: Happy π day! A plain-text version of these NASA π-in-space puzzles are available at
  • March 13th, 2015: Okay, ladies and gentlemen, today, in honor of tomorrow being π day, let's take a #coercive #logic break and π it up!
  • March 12th, 2015: I wonder if the suitor's surname is Quine for today's #haskell problem #coercive #logic
  • March 10th, 2015: For today's #haskell problem, we wonder if Balikaya is Aharmanite or Mazdaysian #scheherazade #coercive #logic
  • March 9th, 2015: In which Iskandar is asked Kamar's Children's ages in Scheherazade's #haskell metapuzzle #coercive #logic 
  • March 6th, 2015: Champernowne's constant for today's #haskell problem Please let me know if you can NOT access this problem: I've marked it private as previous ones are being modified in place. DON'T DO THAT!  In which we show @geophf triumphs with brütish-forcisms for today's #haskell solution
  • March 5th, 2015: For today's #haskell problem, we ponder why they aren't calledLEFT-triangles. Is it a plot? Leftist triangles are subject to the (IO) State (monad) ... geddit? #sigh never mind anyway, solution: Or, put another way: in which we see @geophf can not have a function type that includes -> Int -> ... AND, we really need MapReduce here!
  • March 4th, 2015: Truncatable primes (11 in all) are asking to be solved in today's #haskell problem This @1HaskellADay problem turned into a _TWO_day solution! Worth it? Why, yes, after redesigning _TWO_ libraries!
  • March 3rd, 2015: There's more than a 1-in-a-million chance there are 'sum' double palindromic numbers in today's #haskell problem The solution was not too hard, M. Euler!
  • March 2nd, 2015: What-what! abcde * fghij is equal to ... well, something, it appears. and the prob1, prob2 winners are ... A solution to today's #haskell problem.

Sunday, March 1, 2015

February 2015 1HaskellADay Problems and Solutions

February 2015
  • February 27th, 2015: Let's put all our primes in a circle, shall we? Ah, how cute! Today's #haskell problem suggested by @jamestanton @bretthall defines a solution, with some analysis, at
  • February 26th, 2015: Okay, check this! Today's #haskell problem is as easy as 1, 2, 3! An easy as π solution is posted at ... mmm! π! But is it apple π or ... raspberry π? #couldntresist
  • February 25th, 2015: I'd like moccha sprinkles on my double capicua, please. No. Wait. Today's #haskell problem suggested by a tweet from @OnThisDayinMath
  • February 24th, 2015: Not satisfied with a simple square-from-square problem @BenVitale takes it up a notch and asks us to cube dat square! We have one solution out of 20k squares posted at : [(39204,39304)]
  • February 23rd, 2015: I hereby christen this week a fun-with-numb3rs week, and start us off by learning that 'easierest' is a word,, just like 'ginormous.' And the winner, wait! Ladies and gentlemen, we have MULTIPLE winners! Good thing the solution isn't the Lotto No, wait. The problem statement wasn't read carefully by the solution-poster. I blame that wicked, wicked @geophf! Bad geophf! Bad! ;)
  • February 20th, 2015: It's a #Borderlands2 Truxican Standoff for you to resolve in today's #haskell problem The solution is simple really: just a projection into a monad category in order to do some monoidal deduction is all!
  • February 19th, 2015: For today's #haskell problem we learn that 'AEKL' is a word in English (no, it's not, actually) A megalokaryocyte-solution is posted at (now, that's a common word ... NOT! ;)
  • February 18th, 2015: Instead of doing today's #haskell problem, let's go ice skating. No, let's do BOTH! Okay, a loquacious solution? garrulous? Yes. Once one cuts through all the attempts, it's a simple solution, too: ... and updated the solution with the monoidal guarantee-by-implication that the result is unique (instead of just hoping it is) #coercivelogic
  • February 17th, 2015: For today's #haskell problem we are asked to 'fix' our monetary problems (or the library, at least) Made Data.Monetary.USD a Fractional instance and eliminated floating point creep #haskell #money #precision 
  • February 16th, 2015: Getting a jump-start on the day with two really, really hard math problems for today's #haskell problem A solution in which we learn a baseball costs a nickel ... IN WHICH CENTURY?
  • February 13th, 2015: Today's SCARY #haskell problem comes by way of @OnThisDayinMath Tonight's late-night movie, Friday the 13th, part III as the solution to today's #haskell problem.
  • February 12th, 2015: Gurer ner gvzrf jura ... yeah. That. Today's #haskell problem, thanks to @KenKenPuzzle The solution shows us that it's INTENSE unscrambling words
  • February 11th, 2015: Change adds up quickly in today's #haskell problem So, but ... does that mean programming is like ... maths? Nah! A solution to today's #haskell problem
  • February 10th, 2015: The price of a letter (or of all letters of the alphabet) is the question for today's haskell problem. In the solution we learn the geophfmeister is down-low on the B.I.G. 323, yo!
  • February 9th, 2015: 'Oh, no!' ... just another Manic Monday ... AND today's #haskell problem Oh, noes! Mr. Bill! A solution to the oh, no!-problem.
  • February 6th, 2015: It's Friday! Friday! Hava #haskell problem on Friday! Fun-fun-fun! Lookin' forward to the weekend! Groovin' to aRebecca Black solution at
  • February 5th, 2015: Triangles and Squares as numbers for today's Haskell problem. A Triangulated-squares solution is provided by @bretthall at
  • February 4th, 2015: Three birds in the hand is better than today's #haskell problem an ornithologist's delight inspired by @KenKenPuzzle. The solution, using MultiMaps, PartitionedSets, and Arrows is (@geophf-obviously) "WOOT! WOOT! WOOT!"
  • February 3rd, 2015: We entertain a foolish attempt at a #haskell problem, and then we get serious with six sewing seamstresses A silly seamstress solution is posted at 
  • February 2nd, 2015: Today's #haskell exercise is all about the #SuperBowl! (No, it's not, but that makes for good copy), or 110, 210, ... The moral (and solution) to this story is: Don't eat cheerios seasoned with basil. Or something like that. Inspired by @bretthall solution, I expanded to include last-3-of-4 digits for solutions to bases 4,5,6 @jamestanton

Sunday, February 1, 2015

January 2015 1HaskellADay Problems and Solutions

January 2015
  • January 30th, 2015: Catted Prime Factors Today's answer shows us composed primes. No. Wait. Primes aren't composed, by definition, right? Well, anyway...
  • January 29th, 2015: For today's haskell problem we peace-out by making triangles, not war. And our solution: make my day, punk! ... with triangles (extra-spicy, please)! Bleh, our non-partial solution: no fun, no triangles! Can you fix it?
  • January 28th, 2015: Criss-cross; APPLESAUCE! ... butnot Christopher Cross for today's Haskell problem. Anndddd, safety first, or don't cross that yellow line! for today's solution.
  • January 27th, 2015: What's 'All in the Family'? Elegance is. Today's Haskell problem is about a little bit more elegance. And lines. And triangles. Our solution involves slopes and stuff ... from Elementary School. Remember?
  • January 26th, 2015: Just a simple counting-triangles problem using Data.Graph for today's #haskell problem In our solution we put the triangles into a  Graph, counting crows ... I meant: 'triangles.' 
  • January 23rd, 2015: A simple request on this fine Friday: solve the 'aug'mented matrix for today's #haskell problem Row-echelon solverSOLVED! (WOOT!s included for free!)
  • January 22nd, 2015: Row-echelon form; not solved yet, but PDC! ('pretty durn closer!') Aug! Our matrix has been row-echeloned! A solution for today's Haskell problem.
  • January 21st, 2015: Vectors are Num(bers), too ... adding two (same-length) vectors for today's Haskell problem ... and rollin' the vector-addition solution is posted at
  • January 20th, 2015: May I introduce Miss Abby Normal for today's Haskell problem? Vector normalization for reduced row-echelon form. NORM! A solution to today's Haskell problem is CHEERSfully posted at
  • January 19th, 2015: Oh, something new for today's #haskell problem? Well, then: how about a ... MATH PROBLEM! ... 'sorta' Eheh. We have a guest who decided to solve the problem: Þor (Thor). THOR SMASH! No. Wait. That's the Hulk. Never mind.
  • January 16th, 2015: Let it snow, let it snow, let it matrix-solver! for today's #haskell problem with (Ooh! Ooh!) pretty matrix pictures!
Picture. Terminal. Snowflake-matrix. BlinchtenLightzen.
  • January 15th, 2015: n, k, and b are all you need (oh, and the answers) for today's Haskell problem
  • January 14th, 2015: More fun with fractals for today's #haskell problem: plotting the Harriss Spiral
  • January 13th, 2015: Yesterday we did not learn about the (constructive?) truth of 2+2 = 4. Sorry. Today we try to equate two circled rows
  • January 9th, 2015: In which it is shown that snarkiness is unavoidable when @geophf presents a Mensa-puzzle for today's #haskell problem
  • January 8th, 2015: Cressida, a smart little girl (in fact: a Mensan), would like you to determine her age for today's #haskell problem
  • January 7th, 2015: Fibbing down-low on the fibs! for today's haskell problem
  • January 5th, 2015: I'm looking over a 4-leaf tuple/That I overlooked before! #haskell problem today: over definition for Lens-on-tuples A solution is 'overdefined' by @bretthall at
  • January 4th, 2015: It's a new year, and I've just woken up and smelled the Lens-coffee! Bob Marley welcomes you to the New Year with a #haskell problem about #lenses Sing with me! set _2 "love" (1, 2) A solution is offered by @bretthall at

Sunday, January 4, 2015

December 2014 1HaskellADay Problems and Solutions

December 2014
  • December 30th, 2014: Why can't we all just consensus along? for today's Haskell problem Pro-, con-, anti-, ... it's all sensus to me!
  • December 29th, 2014: Uh, wait! What? It's another day? We need another #haskell puzzler? Here ya go! Rosalind subs (not grinders) Rose petals falling ... and a soution to the #rosalind subs problem
  • December 24th, 2014: A||B||C == Merry Christmas for today's haskell problem
  • December 23rd, 2014: Convergence, but not the movie, is today's #haskell problem A rational solution was posted by @sheshanaag at 
  • December 22rd, 2014: Yesterday was about the zeroes, today's haskell problem is about the squares
  • December 21nd, 2014: In which we want to have the most zeros. Fancy that! (I guess we're not playing Dodgeball, then!)
  • December 19th, 2014: A question for today's #haskell problem: how do YOUclear a Writer monad's log? A FlushableWriter solutionwas posted by @aditcr8 at
  • December 18th, 2014: Why can't you spell 'PROTEIN' with proteins? The solution for this problem is to Eat your proteins, young man!
  • December 17th, 2014: In which we find out that Mendel was into the Domme-scene for today's #haskell problem Whether hetero- or homo- a zygous is still a zygous... whatever that is. A solution to today's #haskell-zygous problem is posted at
  • December 16th, 2014: All actors should relate to today's #haskell problem; it's all about H-A-M-M! Go HAMM it up; #Rosalind will love you. And the solution is so HAMMy!
  • December 15th, 2014: Wanna Date? In which Jane Austen writes today's #haskell problem in her modern book titled: "The Hook Up" aka Pride and Prejudice. To get to our solution space, first we have to write an l-expr scanner/parser, of course.
  • December 12th, 2014: In this case 'GC' does NOT mean 'garbage collection' for today's #rosalind #haskell problem Yeah, not garbage-collected, but a solution, nonetheless 
  • December 11th, 2014: Why ... you ... wascally wabbit! Today's #haskell problem has a solution multiplying like Fibonaccis! I mean: rabbits. And speaking of rabid rabbits, the solution is there. BLARGH! 
  • December 10th, 2014: "Hello, Strand, you're looking lovely in that dress!" Complimenting DNA for today's #haskell problem. No, wait: 'comPLEmenting' a strand of DNA. Sorry, Miss Rosalind! A nicely complimented solution to the DNA-complement problem posted at
  • December 9th, 2014: I think this is my week with dear Rosalind: DNA-to-RNA transcriber for today's #haskell problem Another #TweetedHaskellSolution posted to for today's DNA-to-RNA transcriber
  • December 8th, 2014: Rosalind, dear Rosalie, wherefore art thou givest me bioinformatic puzzles to solve, counting nucleotides? #haskell Nucleotide-counter, HO! A nucleotide-counting solution is posted at 
  • December 5th, 2014: This visit to Liar's-berg (or is it Truth-town?) we encounter only two women, so this should be 2x as easy to solve By coercion, we find that we are in Liarsberg, after all:
  • December 4th, 2014: Gadzooks! It's (past) that time of day again for the daily #haskell problem. Here: eat some glow worms!
  • December 3rd, 2014: Substantive citizens (with some substantive hints, for a change) for today's #haskell problem
  • December 2nd, 2014: There are some curious fractions to find for today's #haskell problem at Asolution to this curious fraction problem is posted at
  • December 1st, 2014: Today's Haskell problem is all about lambda-terms. It has NOTHING to do with for-loops and if-statements, ... NOT ONE BIT Solution: 

Monday, December 8, 2014

10 programming challenge sites

Okay. Whoa!

I saw this off the twitter feed: Ten programming challenge sites

And, from it, I have a new love affair:, a problem-solving site for bioinformatics. I love it. What's not to love!

Monday, December 1, 2014

November 2014 1HaskellADay Problems and Solutions

November 2014
  • November 3st, 2014: Let it snow, let it snow, let it ... lambda for today's #haskell problem ... and the answer is Snow Mittens for Snow Kittens! YAY!
  • November 4nd, 2014: At the First National Bank the MEN like to play chess with each other Today's #haskell problem. Men in banks like playing chess with each other come to find in the solution to today's #haskell logic puzzle
  • November 5th, 2014: Doin' the spiral from, problem 28, for today's #haskell puzzler Heh, I actually spiraled out to the solution for today's #haskell problem.
  • November 6th, 2014: From @BenVitale funwithnumb3rs site, we have a, b, and c ... and how simple can today's #haskell problem be? ;)'s as easy as 1, 2, 3! is our solution to today's problem
  • November 7th, 2014: Making sensical tweets for #ingress for today's #haskell problem A semantical romp through syntax (that is: the solution) is posted at
  • November 10th, 2014: As I embark on my morning commute, I share today's #haskell problem about ... the morning commute! To get to the solution ya gotta keep on truckin'
  • November 11th, 2014: Some Coin sums. In for a penny, in for a £ for today's #haskell problem Solution coded, but is it the correct one for counting coins? How did you do it? HA! I found the problem with my counting-coins solution! Redundancies! Updated solution at
  • November 12th, 2014: Squares, Cubes and Triangles masquerade as numbers in today's #haskell problem The square by a cube of a triangle is our digit-picking solution to today's math puzzle
  • November 13th, 2014: It's all about making the grade. I MEANT: 'THE SEARCH FOR TRUTH'! Yeah, THAT's what I meant. Not: 'making the grade.' Translation: Today's #haskell problem is about making the grade. I MEANT 'SEEKING KNOWLEDGE'! Yeah. That's what I meant. *blush* Isabella makes the grade in today's equational solution (rant by @geophf provided free of charge).
  • November 14th, 2014: 0h, h1 there! for today's #haskell puzzle
  • Our bonus solution is coded here (, and looks like this:

  • November 17th, 2014: The in-laws bump into Amy and her baby in the perambulator on her daily stroll for today's #haskell problem For today's solution we find a really roundabout way to say 'brother-in-law' And the bonus solution( we graph it with Neo4J:

  • November 18th, 2014: Would you like some chips with that Fish? The #haskell puzzler for today is a 'SOLE' word-square Sole Open Ends Lead! A newspaper-escque headline-y-like solution to today's Haskell puzzler
  • November 19th, 2014: Next Mensa puzzler for today's #haskell problem. Who gotfirst place in the science fair? Woman Power! A solution to today's Haskell puzzler
  • November 20th, 2014: "Trick or treat!" But how many bags of candy did the new cashier, to be named later, sell? Solve this to let her know. The solution is posted here ( and graphed out ... for 'funzies.'
  • November 21st, 2014: Her Majesty, Queen Victoria (Vicky or Maj to her buds) (not really), has a #haskell poem-puzzler for you: (Standard disclaimer: we make no representation of reigning monarchs, living or dead, implied or otherwise. Besides... the Queen has no buds.) So, that brings to mind two thoughts, or pensées: 
  1. you see how I used the royal-'we' there? ;)
  2. 2) How sad to be Queen, and have no buds :(
    (@1HaskellADay In which it is learned it is a sadness to be Queen, to have no buds withal. :( *sniffle*) The 'clever' solution ( comes even with its own 'TA-DAH!' ... gratis. You're welcome.

    • November 24th, 2014: Circular primes, from, is today's #haskell puzzler: A solution to the circular primes problem is posted at 
    • November 25th, 2014: Have a well-ordered (re)presentation of today's #haskell problem  Suffice to say: today's 'date' is 'fig.' geddit? ;) A solution is a (sorta) logical calendar 
    • November 26th, 2014: Got a question for ya! for today's Haskell 1-9 in so many ways
    • November 27th, 2014: Happy Thanksgiving to all you Haskell aficionados out there! Today's #haskell puzzle set involves da turkeyzzzz! That there is a lot of turkey!
    • November 28th, 2014: Black Friday. OKAY, FOLKS! TODAY, AND _ONLY_ TODAY, EVERYTHING IS ON SAAAAAAAALLLLEEEE! Today's Black Friday #haskell problem. THESE PRICES ARE ...INSAAAAANNNNEEE! A solution to today's Black Friday logic puzzle.