Data commit

Task/Roman-numerals-Encode/Erlang/roman-numerals-encode-1.erl

@@ -0,0 +1,20 @@
+-module(roman).
+-export([to_roman/1]).
+
+to_roman(0) -> [];
+to_roman(X) when X >= 1000 -> [$M | to_roman(X - 1000)];
+to_roman(X) when X >= 100 ->
+    digit(X div 100, $C, $D, $M) ++ to_roman(X rem 100);
+to_roman(X) when X >= 10 ->
+    digit(X div 10, $X, $L, $C) ++ to_roman(X rem 10);
+to_roman(X) when X >= 1 -> digit(X, $I, $V, $X).
+
+digit(1, X, _, _) -> [X];
+digit(2, X, _, _) -> [X, X];
+digit(3, X, _, _) -> [X, X, X];
+digit(4, X, Y, _) -> [X, Y];
+digit(5, _, Y, _) -> [Y];
+digit(6, X, Y, _) -> [Y, X];
+digit(7, X, Y, _) -> [Y, X, X];
+digit(8, X, Y, _) -> [Y, X, X, X];
+digit(9, X, _, Z) -> [X, Z].

Task/Roman-numerals-Encode/Erlang/roman-numerals-encode-2.erl

@@ -0,0 +1,20 @@
+-module( roman_numerals ).
+
+-export( [encode_from_integer/1]).
+
+-record( encode_acc, {n, romans=""} ).
+
+encode_from_integer( N ) when N > 0 ->
+        #encode_acc{romans=Romans} = lists:foldl( fun encode_from_integer/2, #encode_acc{n=N}, map() ),
+        Romans.
+
+
+encode_from_integer( _Map, #encode_acc{n=0}=Acc ) -> Acc;
+encode_from_integer( {_Roman, Value}, #encode_acc{n=N}=Acc ) when N < Value -> Acc;
+encode_from_integer( {Roman, Value}, #encode_acc{n=N, romans=Romans} ) ->
+        Times = N div Value,
+        New_roman = lists:flatten( lists:duplicate(Times, Roman) ),
+        #encode_acc{n=N - (Times * Value), romans=Romans ++ New_roman}.
+
+map() -> [{"M",1000}, {"CM",900}, {"D",500}, {"CD",400}, {"C",100}, {"XC",90}, {"L",50}, {"XL",40}, {"X",10}, {"IX",9}, {"V",5}, {"IV",4}, {"I\
+",1}].