2016 Update

Task/Set-puzzle/00DESCRIPTION

@@ -1,29 +1,28 @@
 {{omit from|GUISS}}
 
-Set Puzzles are created with a deck of cards from the [[wp:Set (game)|Set Game™]]. The object of the puzzle is to find sets of 3 cards in a rectangle of cards that have been dealt face up. <br>
+Set Puzzles are created with a deck of cards from the [[wp:Set (game)|Set Game™]]. The object of the puzzle is to find sets of 3 cards in a rectangle of cards that have been dealt face up. <br><br>
 There are 81 cards in a deck.
 Each card contains a unique variation of the following four features: ''color, symbol, number and shading''.
 
-; there are three colors: '''red''', '''green''', or '''purple'''
+* there are three colors:<br> &nbsp;&nbsp;&nbsp;''red, green, purple''<br><br>
 
-; there are three symbols: '''oval''', '''squiggle''', or '''diamond'''
+* there are three symbols:<br> &nbsp;&nbsp;&nbsp;''oval, squiggle, diamond''<br><br>
 
-; there is a number of symbols on the card: '''one''', '''two''', or '''three'''
+* there is a number of symbols on the card:<br> &nbsp;&nbsp;&nbsp;''one, two, three''<br><br>
 
-; there are three shadings: '''solid''', '''open''', or '''striped'''
+* there are three shadings:<br> &nbsp;&nbsp;&nbsp;''solid, open, striped''<br><br>
 
-Three cards form a ''set'' if each feature is either the same on each card, or is different on each card. <br>
-For instance: all 3 cards are red, all 3 cards have a different symbol, all 3 cards have a different number of symbols, all 3 cards are striped.
+Three cards form a ''set'' if each feature is either the same on each card, or is different on each card. For instance: all 3 cards are red, all 3 cards have a different symbol, all 3 cards have a different number of symbols, all 3 cards are striped.
+
+There are two degrees of difficulty: [http://www.setgame.com/set/rules_basic.htm ''basic''] and [http://www.setgame.com/set/rules_advanced.htm ''advanced'']. The basic mode deals 9 cards, that contain exactly 4 sets; the advanced mode deals 12 cards that contain exactly 6 sets.
 
-There are two degrees of difficulty: [http://www.setgame.com/set/rules_basic.htm ''basic''] and [http://www.setgame.com/set/rules_advanced.htm ''advanced'']. <br>
-The basic mode deals 9 cards, that contain exactly 4 sets;
-the advanced mode deals 12 cards that contain exactly 6 sets.
 When creating sets you may use the same card more than once.
+<br><br>
 
-;The task:
-Is to write code that deals the cards (9 or 12, depending on selected mode) from a shuffled deck in which the total number of sets that could be found is 4 (or 6, respectively); and print the contents of the cards and the sets.
+;Task
+Write code that deals the cards (9 or 12, depending on selected mode) from a shuffled deck in which the total number of sets that could be found is 4 (or 6, respectively); and print the contents of the cards and the sets.
 
-For instance:
+For instance:<br><br>
 
 '''DEALT 9 CARDS:'''
 
@@ -44,7 +43,7 @@ For instance:
 :red, three, oval, open
 
 :red, three, diamond, solid
-
+<br>
 '''CONTAINING 4 SETS:'''
 
 :green, one, oval, striped
@@ -73,3 +72,4 @@ For instance:
 :purple, two, squiggle, open
 
 :purple, three, oval, open
+<br><br>

Task/Set-puzzle/Elixir/set-puzzle.elixir

@@ -0,0 +1,54 @@
+defmodule RC do
+  def set_puzzle(deal, goal) do
+    {puzzle, sets} = get_puzzle_and_answer(deal, goal, produce_deck)
+    IO.puts "Dealt #{length(puzzle)} cards:"
+    print_cards(puzzle)
+    IO.puts "Containing #{length(sets)} sets:"
+    Enum.each(sets, fn set -> print_cards(set) end)
+  end
+
+  defp get_puzzle_and_answer(hand_size, num_sets_goal, deck) do
+    hand = Enum.take_random(deck, hand_size)
+    sets = get_all_sets(hand)
+    if length(sets) == num_sets_goal do
+      {hand, sets}
+    else
+      get_puzzle_and_answer(hand_size, num_sets_goal, deck)
+    end
+  end
+
+  defp get_all_sets(hand) do
+    Enum.filter(comb(hand, 3), fn candidate ->
+      List.flatten(candidate)
+      |> Enum.group_by(&(&1))
+      |> Map.values
+      |> Enum.all?(fn v -> length(v) != 2 end)
+    end)
+  end
+
+  defp print_cards(cards) do
+    Enum.each(cards, fn card ->
+      :io.format "  ~-8s  ~-8s  ~-8s  ~-8s~n", card
+    end)
+    IO.puts ""
+  end
+
+  @colors   ~w(red green purple)a
+  @symbols  ~w(oval squiggle diamond)a
+  @numbers  ~w(one two three)a
+  @shadings ~w(solid open striped)a
+
+  defp produce_deck do
+    for color <- @colors, symbol <- @symbols, number <- @numbers, shading <- @shadings,
+      do: [color, symbol, number, shading]
+  end
+
+  defp comb(_, 0), do: [[]]
+  defp comb([], _), do: []
+  defp comb([h|t], m) do
+    (for l <- comb(t, m-1), do: [h|l]) ++ comb(t, m)
+  end
+end
+
+RC.set_puzzle(9, 4)
+RC.set_puzzle(12, 6)