diff options
| -rwxr-xr-x | 010/ch1.pl | 50 |
1 files changed, 27 insertions, 23 deletions
@@ -3,23 +3,26 @@ use strict; use warnings; +# CLI usage sub usage { - print "$0 {-e LATIN | -d ROMAN}\n"; + print "$0 {-e ARABIC | -d ROMAN | --test}\n"; exit shift; } - -usage -1 unless @ARGV == 2 || $ARGV[0] eq "--test"; - -if ($ARGV[0] eq "-d") { - print decode($ARGV[1]), "\n"; -} elsif ($ARGV[0] eq "-e") { - print encode($ARGV[1]), "\n"; -} elsif ($ARGV[0] eq "--test") { +usage -1 unless @ARGV > 0; +if ($ARGV[0] eq "--test") { test(); } else { - usage -1; + usage -1 unless @ARGV == 2; + if ($ARGV[0] eq "-d") { + print decode($ARGV[1]), "\n"; + } elsif ($ARGV[0] eq "-e") { + print encode($ARGV[1]), "\n"; + } else { + usage -1; + } } +# roman -> arabic sub decode { my @roman = split //, shift; # Decimal value of each roman symbol @@ -32,7 +35,7 @@ sub decode { V => 5, I => 1, ); - my $latin = 0; # Return value + my $arabic = 0; # Return value # Iterate over roman symbols for (my $i = 0; $i < @roman; $i++) { @@ -42,25 +45,26 @@ sub decode { # Sub current value if next symbol is bigger; add it otherwise if (defined $nextsym && $val < $dec{$nextsym}) { - $latin -= $val; + $arabic -= $val; } else { - $latin += $val; + $arabic += $val; } } - return $latin; + return $arabic; } +# arabic -> roman sub encode { die "ERROR: Unable to encode numbers bigger than 9999" if $_[0] > 9999; - my @latin = split //, shift; + my @arabic = split //, shift; my @symbols = ("I", "V", "X", "L", "C", "D", "M"); my @roman; # Return value (roman symbols) - # Iterate latin digits from right to left (upward units) - for (my $i = $#latin; $i >= 0; $i--) { - my $digit = $latin[$i]; + # Iterate arabic digits from right to left (upward units) + for (my $i = $#arabic; $i >= 0; $i--) { + my $digit = $arabic[$i]; # Roman symbols corresponding to (1-5-10) given the current base my ($one, $five, $ten) = @symbols; @@ -95,12 +99,12 @@ sub encode { } # Property: -# forall (x : Latin). x == decode(encode(x)) +# forall (x : Arabic). x == decode(encode(x)) sub test { - foreach my $i (1..9999) { - my $roman = encode($i); - my $latin = decode($roman); - die "ERROR: $i -> $roman -> $latin" if $i != $latin; + foreach my $i (1..9999) { + my $roman = encode($i); + my $arabic = decode($roman); + die "ERROR: $i -> $roman -> $arabic" if $i != $arabic; } print "Test successful\n"; } |