output.txt

awwaiid@misao:~/dcpm$ perl randori-2010301-roman.pl           
shift on reference is experimental at randori-2010301-roman.pl line 25.
shift on reference is experimental at randori-2010301-roman.pl line 68.
ok 1 - Simple 1 works
ok 2 - Real simple 2 works
ok 3 - We have prepended values!
ok 4 - We have Vs
ok 5 - seventeen and stuff
ok 6 - nineteen and stuff
ok 7 - twenty and stuff
ok 8 - fourty and stuff
not ok 9 - fourty one
#   Failed test 'fourty one'
#   at randori-2010301-roman.pl line 84.
#          got: 'XXXXI'
#     expected: 'XLI'
not ok 10 - Fourty NINE
#   Failed test 'Fourty NINE'
#   at randori-2010301-roman.pl line 85.
#          got: 'IL'
#     expected: 'XLIX'
ok 11 - NINETY YO
not ok 12 - NINETY NINE YO
#   Failed test 'NINETY NINE YO'
#   at randori-2010301-roman.pl line 87.
#          got: 'IC'
#     expected: 'XCIX'
ok 13 - base of 41 good
ok 14 - Got good base
not ok 15 - Can do fancy subtraction
#   Failed test 'Can do fancy subtraction'
#   at randori-2010301-roman.pl line 90.
#          got: 'LXXXXVIV'
#     expected: 'XCIX'
1..15
# Looks like you failed 4 tests of 15.

randori-2010301-roman.pl

#!/usr/bin/env perl

use v5.20;

use Test::More;

our %numerals = (
  1 => "I",
  5 => "V",
  10 => "X",
  50 => "L",
  100 => "C",
  500 => "D",
  1000 => "M"
);

our @radix = sort {$a <=> $b} keys %numerals;

our @bases = @radix[2, 4, 6];

sub to_roman {
  my $number = shift;

  # say "Working on $number";
  my $smaller = shift [reverse grep {$_ < $number} @radix];

  if(defined $numerals{$number}) {
    return $numerals{$number};
  }
  elsif(defined $numerals{$number+100}) {
    return 'C' . $numerals{$number+100};
  }
  elsif(defined $numerals{$number+10}) {
    return 'X' . $numerals{$number+10};
  }
  elsif(defined $numerals{$number+1} ) {
    return 'I' . $numerals{$number+1};
  }
  elsif($number < 4) {
    return "I" x $number;
  }

  return $numerals{$smaller} . to_roman($number - $smaller);
}

sub subtraction {
  my $number = shift;
  my $base = base($number);

  my $base_roman = to_roman($base);

  my @radix = keys %numerals;
  my $smaller_radix = [grep { $_ < $number} @radix];
  # say "smaller_radix: @$smaller_radix";
  my $smaller = $smaller_radix->[-2];
  # say "smaller: $smaller";

  # $number  = 99
  # $base    = 100
  # $smaller = 10
  # $base - $smaller = 90

  return to_roman($base - $smaller) . to_roman($number - ($base - $smaller));
}

sub base {
  my $number = shift;
  my $larger = shift [grep {$_ > $number} @radix];
  return $larger;
}

# for my $n (1..50) {
#   say to_roman($n);
# }

is to_roman(1), "I", "Simple 1 works";
is to_roman(2), "II", "Real simple 2 works";
is to_roman(4), "IV", "We have prepended values!";
is to_roman(5), "V", "We have Vs";
is to_roman(17), "XVII", "seventeen and stuff";
is to_roman(19), "XIX", "nineteen and stuff";
is to_roman(20), "XX", "twenty and stuff";
is to_roman(40), "XL", "fourty and stuff";
is to_roman(41), "XLI", "fourty one";
is to_roman(49), "XLIX", "Fourty NINE";
is to_roman(90), "XC", "NINETY YO";
is to_roman(99), "XCIX", "NINETY NINE YO";
is base(41), 50, "base of 41 good";
is base(99), 100, "Got good base";
is subtraction(99), "XCIX", "Can do fancy subtraction";

done_testing;