Added K #4

k/004/004.k

@@ -0,0 +1,33 @@
+/   100+x                                  Dyadic plus. Add 100 to each element in x.
+
+/   !900                                   Monadic enumerate. Returns a list of integers from 0 to 899.
+
+/   {100+x}'!900                           Apply the above plus function to the above list to get a list of integers from 100 to 999.
+
+/   g:{100+x}'!900                         Assign the above list of integers to variable g.
+
+/   {x*g}'g:{100+x}'!900                   Dyadic multiply. Muliply each element in g by each element in g returning a list of lists of multiples for each element in g.
+
+/   ,/{x*g}'g:{100+x}'!900                 Apply dyadic join to the above list of lists.
+
+/   f:,/{x*g}'g:{100+x}'!900               Assign the above list of multiples to variable f.
+
+/   $f:,/{x*g}'g:{100+x}'!900              Monadic format. Convert each element in the above list to strings.
+
+/   |x                                     Monadic reverse. Reverses x, in this case as string.
+
+/   x~|x                                   Dyadic match. In this case matches x with its reverse returning 1 if they're the same and 0 if not.
+
+/   {x~|x}'$f:,/{x*g}'g:{100+x}'!900       Apply the above to the previous list of strings.
+
+/   &{x~|x}'$f:,/{x*g}'g:{100+x}'!900      Monadic where. Gets the indices of the previous that are 1.
+
+/   f@&{x~|x}'$f:,/{x*g}'g:{100+x}'!900    Dyadic at. Gets elements at the previous indices from variable f.
+
+/   |/f@&{x~|x}'$f:,/{x*g}'g:{100+x}'!900  Dyadic max/or over the previous.
+
+`0:5:|/f@&{x~|x}'$f:,/{x*g}'g:{100+x}'!900
+
+`0:"\n"
+
+_exit(0)

test/rosetta_euler/k_test.exs

@@ -17,7 +17,7 @@ defmodule RosettaEuler.KTest do
     System.cmd("k", [name <> ".k"], cd: Path.join("k", name))
   end
 
-  rosetta_euler_tests 1..3 do
+  rosetta_euler_tests 1..4 do
     @tag test_number: test_number
     test "K #" <> to_string(test_number), %{test_number: test_number} do
       answer = answer_for(test_number) <> "\n"