July 2020 1HaskellADay Problems and Solutions

• 2020-07-13: Now that we've selected pairings for today, let's store those pairings into an historical context for today's #haskell problem. 
• 2020-07-08: Pairing and ... 'Mobbing' (?) ... okay, really??? is our game for today's #haskell problem. A solution to the simple pairing-problem.
• 2020-07-07: For today's #haskell problem, we lay a foundation for building a team-pairing app. This day's problem addresses a History-type to provide context to the pairing-algorithm. 
• 2020-07-06: For today's #haskell problem, we look at finding the spanning trees of a graph. 
  
• 2020-07-02: Today's #haskell exercise finds us (acyclic) pathing though a simpler, yet-not-fully connected, graph. 
  
• 2020-07-01: For today's #haskell problem we find cycles in graphs, ... MOTORcycles in graphs! AHA! AND MAKE MINE A DUCATI! ON FYE-YARRRR! 🔥 ... no ... wait ... Oh, well. #GraphTheory 
  

June 2020 1HaskellADay Problems and Solutions

YAY! HELLO! Our first #haskell exercise in a while!... and this exercise is about ... wait for it ... exercise! 

For today's #haskell exercise we convert a set of arcs to a graph. #GraphTheory 

February 2019 1HaskellADay Problems and Solutions

• February 20th, 2019: Wednesday's #haskell problem: we've got words, now let's find words that start with ... 'x'. 
• February 19th, 2019: Tuesday's #haskell problem: now that we have a word finder, let's pretty-print the results! 
• February 18th, 2019: Monday's #haskell problem is to come up with sets of wordsusing only a set of supplied letters. Monday's #haskell solution has some trickiness around empty sets: this, we call 'fun.' 

April/May 2019 1HaskellADay 1Liners

• May 27th, 2018:
  data F = F { a, b, c :: String }
  data Stamped a = { time :: Day, stamped :: a }
  
  f :: Stamped F -> String
  
  output of f x is  "time a b c" for the respective values of time, a, b, c
  
  Is there some monadic / applicative elegant definition that does this?
• Nickolay Kudasov @crazy_fizruk
  f = intercalate “ “ . sequence [ show.time, a.stamped, b.stamped, c.stamped ]
• Nickolay Kudasov @crazy_fizruk
  f = intercalate " " <$> http://pure.show .time <> (sequence [a, b, c]).stamped
  A bit trickier, but shorter and uses stamped once.
• April 13th, 2018: given f :: [a] -> b -> [c]
  where c is a derived from g :: a -> b -> c
  
  You have [a] and [b]
  
  Write a function h :: [a] -> [b] -> [c] from f

January 2019 1HaskellADay Problems and Solutions

• January 30th, 2019: Wednesday's #haskell problem is to take the JSON-y articles and the HTML-encoded articles and sort them by id and by date. 
• January 29th, 2019: For Tuesday's #haskell problem we convert JSON-like strings to valid HTML strings, handling irregularities (gracefully!) in the input data as we go. For Tuesday's #haskell solution we convert text to text when you're not sure of the structure a priori. 
• January 28th, 2019: Hello, Haskellers! Happy New Year! Monday's #haskell problem is a little warming-up JSON parsing exercise to get back into the swing of things. Monday's #haskell solution uses the Data.Aeson library to parse the JSON into Haskell data structures. 

December 2018 1HaskellADay Problems and Solutions

• December 19th, 2018: Tuesday's #haskell problem was to eliminate that pesky plus-sign; Wednesday's haskell problem is to enputify it back in! A solution of enputification.
• December 18th, 2018: Tuesday's #haskell problem is to sum a set of integers from file ... except the integers are stored with a novel representation. Tuesday's #haskell solution eliminates that pesky plus-sign, and, doing that, you get yourself a gold star from the adventofcode.com  
  
• December 5th, 2018: Wednesday's #haskell problem: from KAYAK to ULULU, generalizing the palindrome-grid puzzle. Wednesday's #haskell solution: ULULU, RADAR, or any word you want can be engridified (that's a word, now) 
  
• December 4th, 2018: Tuesday's #haskell problem is to find 5-letter palindromes in your word dictionary. Tuesday's #haskell solutions finds 'ULULU'! Now, that's another KAYAKescque word! 
• December 3rd, 2018: Monday's #haskell problem is scanning a sea of A's, K's, and Y's for a KAYAK.  Monday's #haskell solution is a kayak found, now that I remember where I placed it. 

November 2018 1HaskellADay Problems and Solutions

• November 27th, 2018: Tuesday brings a little more logic to today's #haskell puzzler. 
  
• November 26th, 2018: Monday's #haskell problem: J'ACCUSE! 
• November 23rd, 2018: A little late, but here's a little logic puzzle to solve using #haskell on a frigid Friday. That took a couple of iterations, but BOOM! a #haskell solution to Friday's little logic puzzle. 
  
• November 22nd, 2018: Thursday's #haskell problem is from @fermatslibrary: we throw enough 1/4th together and we get 1/3. Trust me on this one. 
  
• November 21st, 2018: From @fermatslibrary comes Wednesday's #haskell problem For Wednesday's #haskell solution: π and e as an equality? How transcendent! ... eheh. 😎 
  
• November 5th, 2018: Monday's #haskell problem: rectangular numbers from a calculator face are all divisible by 11. True? The #haskell solution shows that yes, it is true! 
  
   
• November 2nd, 2018: From @fermatslibrary comes Friday's #haskell problem: twoSquaresDifference of any odd number. Friday's #haskell solution we are folding odd numbers to find their diff squares.