Merge pull request #192 from mienaikage/bruteforce

Add concurrent bruteforce roman decoder

1 files changed, 36 insertions, 9 deletions

diff --git a/challenge-010/daniel-mita/perl6/ch-1.p6 b/challenge-010/daniel-mita/perl6/ch-1.p6
index 27989b4f2b..7a12b34226 100644
--- a/challenge-010/daniel-mita/perl6/ch-1.p6
+++ b/challenge-010/daniel-mita/perl6/ch-1.p6
@@ -1,12 +1,15 @@
 #!/usr/bin/env perl6
 use v6;
 
+my %*SUB-MAIN-OPTS = :named-anywhere;
+
+my constant @letters   = ｢IVXLCDM｣.comb;
 my constant @overlines = "\c[combining overline]", "\c[combining double overline]";
 
-my constant %letters = ( 1, |( * X* 5, 10 ) … ∞ ) Z=>
-  'I', |('', |@overlines XR~ ｢VXLCDM｣.comb );
+my constant %letter-map = ( 1, |( * X* 5, 10 ) … ∞ ) Z=>
+  |@letters, |( @overlines XR~ @letters[1..*] );
 
-my constant %prefixes = %letters{ 10 X** 3, 6 } Z=> ( %letters<1> X~ @overlines );
+my constant %prefixes = %letter-map{ 10 X** 3, 6 } Z=> ( %letter-map<1> X~ @overlines );
 
 multi MAIN (
   UInt:D $number where 0 < * < 4e9, #= A positive integer.
@@ -18,12 +21,36 @@ multi MAIN (
 #| Not Yet Implemented
 multi MAIN (
   Str:D $roman-numerals
-    where *.uc.comb ⊆ (%letters, %prefixes).map(*.values).flat, #= A string of roman numerals.
   --> Nil
-) {
+) is hidden-from-USAGE {
   say &?ROUTINE.WHY;
 }
 
+multi MAIN (
+  Str:D $roman-numerals where *.chars > 0, #= A string of roman numerals.
+  Bool:D :bruteforce(:$b) where *.so, #= Convert using bruteforce method.
+  --> Nil
+) {
+  given |( @overlines.map(@letters X~ *).reverse ), @letters -> @set {
+    $roman-numerals.uc ~~ / ^ ( @(@set[0])+ )? ( @(@set[1])+ )? ( @(@set[2])+ )? $ /;
+  }
+
+  if $/ {
+    given await gather {
+      take Promise.start( { (1..^4000).race.map(* * 1e6).first(*.&to-roman eq $0) } ) if $0;
+      take Promise.start( { (1..^4000).race.map(* * 1e3).first(*.&to-roman eq $1) } ) if $1;
+      take Promise.start( { (1..^4000).race.first(*.&to-roman eq $2) } ) if $2;
+    } {
+      if .all.so && .sum.&to-roman eq $roman-numerals.uc {
+        .sum.say;
+        return;
+      }
+    }
+  }
+
+  say "Error:\n  The input was not understood.\n\n" ~ $*USAGE;
+}
+
 sub to-roman (
   UInt() $_,
   --> Str:D
@@ -32,13 +59,13 @@ sub to-roman (
     for .flip.comb.pairs.reverse {
       given 10 ** .key -> $key {
         when .value == 4 | 9 {
-          take %prefixes{ %letters{$key} } || %letters{$key};
-          take %letters{ $key * (.value + 1) };
+          take %prefixes{ %letter-map{$key} } || %letter-map{$key};
+          take %letter-map{ $key * (.value + 1) };
         }
         if .value ≥ 5 {
-          take %letters{ $key * 5 };
+          take %letter-map{ $key * 5 };
         }
-        take %letters{ $key } x .value % 5;
+        take %letter-map{ $key } x .value % 5;
       }
     }
   };