- Added solutions by Arne Sommer.

- Added solutions by Laurent Rosenfeld.

3 files changed, 121 insertions, 0 deletions

diff --git a/challenge-227/laurent-rosenfeld/blog1.txt b/challenge-227/laurent-rosenfeld/blog1.txt
new file mode 100644
index 0000000000..66db4bdf8e
--- /dev/null
+++ b/challenge-227/laurent-rosenfeld/blog1.txt
@@ -0,0 +1 @@
+https://blogs.perl.org/users/laurent_r/2023/07/perl-weekly-challenge-227-roman-maths.html
diff --git a/challenge-227/laurent-rosenfeld/perl/ch-2.pl b/challenge-227/laurent-rosenfeld/perl/ch-2.pl
new file mode 100644
index 0000000000..26470af669
--- /dev/null
+++ b/challenge-227/laurent-rosenfeld/perl/ch-2.pl
@@ -0,0 +1,63 @@
+#!/usr/bin/perl
+use strict;
+use warnings;
+use feature qw/say/;
+
+my %rom_tab = (I => 1,  V => 5, X => 10, L => 50,
+               C => 100, D => 500, M => 1000,
+               IV => 4, IX => 9,  XL => 40, XC => 90,
+               CD => 400,  CM => 900);
+
+sub from_roman {
+    my $roman = uc shift;
+    my $arabic = 0;
+    my $prev_letter = "M";
+    for my $letter (split //, $roman) {
+        $arabic -= 2 * $rom_tab{$prev_letter}
+            if $rom_tab{$letter} > $rom_tab{$prev_letter};
+        $arabic += $rom_tab{$letter};
+        $prev_letter = $letter;
+    }
+    return $arabic;
+}
+
+sub to_roman {
+    my $arabic = shift;
+    warn "$arabic out of bounds"
+        unless $arabic > 0 and $arabic < 4000;
+    my $roman = "";
+    for my $key (sort { $rom_tab{$b} <=> $rom_tab{$a} }
+        keys %rom_tab) {
+        my $num = int ($arabic / $rom_tab{$key});
+        $roman .= $key x $num;
+        $arabic -= $rom_tab{$key} * $num;
+    }
+    return $roman;
+}
+sub process_input {
+    my ($rom1, $op, $rom2) = split /\s+/, $_[0];
+    my $arabic1 = from_roman $rom1;
+    my $arabic2 = from_roman $rom2;
+    my $result = $op eq '+'  ?  $arabic1 + $arabic2 :
+                 $op eq '-'  ?  $arabic1 - $arabic2 :
+                 $op eq '/'  ?  $arabic1 / $arabic2 :
+                 $op eq '*'  ?  $arabic1 * $arabic2 :
+                 $op eq '**' ?  $arabic1 ** $arabic2:
+                 "illegal";
+    return "nulla (they didn't have a symbol for 0)"
+        if $result == 0;
+    return "non potest (they didn't do fractions)"
+        if int($result) != $result;
+    return "non potest (they only went up to 3999)"
+        if $result >= 4000;
+    return "non potest (no negative numbers)"
+        if $result < 0;
+    return to_roman $result;
+}
+
+for my $test ("IV + V", "M - I", "X / II", "XI * VI",
+              "VII ** III", "V - V", "V / II", "MMM + M",
+              "V - X ", "X - V") {
+    printf "%-10s => ", $test;
+    say process_input $test;
+}
diff --git a/challenge-227/laurent-rosenfeld/raku/ch-2.raku b/challenge-227/laurent-rosenfeld/raku/ch-2.raku
new file mode 100644
index 0000000000..94456d0776
--- /dev/null
+++ b/challenge-227/laurent-rosenfeld/raku/ch-2.raku
@@ -0,0 +1,57 @@
+subset Roman-str of Str where $_ ~~ /^<[IVXLCDMivxlcdm]>+$/;
+
+my %rom-tab = < I 1  V 5  X 10  L 50  C 100  D 500  M 1000
+               IV 4  IX 9  XL 40  XC 90  CD 400  CM 900 >;
+my @ordered_romans = reverse sort { %rom-tab{$_} }, keys %rom-tab;
+
+sub from-roman (Roman-str $roman) {
+    my $numeric = 0;
+    my $prev_letter = "M";
+    for $roman.uc.comb -> $letter {
+        $numeric -= 2 * %rom-tab{$prev_letter}
+            if %rom-tab{$letter} > %rom-tab{$prev_letter};
+        $numeric += %rom-tab{$letter};
+        # say "$letter $numeric";
+        $prev_letter = $letter;
+    }
+    return $numeric;
+}
+
+sub to-roman (Int $arabic is copy where  { 0 < $_ < 4000 }) {
+    my $roman = "";
+    for @ordered_romans -> $key {
+        my $num = ($arabic / %rom-tab{$key}).Int;
+        $roman ~= $key x $num;
+        $arabic -= %rom-tab{$key} * $num;
+    }
+    return $roman;
+}
+sub process-input (Str $in) {
+    my ($rom1, $op, $rom2) = split /\s+/, $in;
+    my $arabic1 = from-roman $rom1;
+    my $arabic2 = from-roman $rom2;
+    my $result;
+    given $op {
+        when '+' { $result = $arabic1 + $arabic2 }
+        when '-' { $result = $arabic1 - $arabic2 }
+        when '*' { $result = $arabic1 * $arabic2 }
+        when '/' { $result = $arabic1 / $arabic2 }
+        when '**' { $result = $arabic1 ** $arabic2 }
+    }
+    return "nulla (they didn't have a symbol for 0)"
+        if $result == 0;
+    return "non potest (they didn't do fractions)"
+        if $result.round != $result;
+    return "non potest (they only went up to 3999)"
+        if $result >= 4000;
+    return "non potest (no negative numbers)"
+        if $result < 0;
+    return to-roman $result.round;
+}
+
+for "IV + V", "M - I", "X / II", "XI * VI",
+  "VII ** III", "V - V", "V / II", "MMM + M",
+  "V - X ", "X - V"  -> $test-expr {
+    printf "%-10s => ", $test-expr;
+    say process-input $test-expr;
+}