diff options
| -rw-r--r-- | challenge-149/james-smith/perl/ch-1.pl | 28 |
1 files changed, 11 insertions, 17 deletions
diff --git a/challenge-149/james-smith/perl/ch-1.pl b/challenge-149/james-smith/perl/ch-1.pl index 16f8bbb711..7cd08cdc48 100644 --- a/challenge-149/james-smith/perl/ch-1.pl +++ b/challenge-149/james-smith/perl/ch-1.pl @@ -8,23 +8,17 @@ use Test::More; use Benchmark qw(cmpthese timethis); use Data::Dumper qw(Dumper); -my $n = @ARGV ? $ARGV[0] : 20; - -my @fib = (0,1,1); -my %fib = (0,1,1,1); - -for(my $i=0; $n; $i++ ) { - my $ds = 0; +# As an array we don't need to keep the fibonacci numbers +# We need them as the keys to the hash %fib which we use +# to check that a digit sum is a fibonacci number. Instead +# We only keep the last two values $fa & $fb +for( my($n,$ds,$i,$fa,$fb,%fib)=(@ARGV?$ARGV[0]:20,0,0,1,1,0,1,1,1); + $n; $i++,$ds=0 ) { $ds+=$_ foreach split //,$i; - if($ds>$fib[-1]) { - ## If we dont have a large enough fib add the next one... - ## Digit sum can only be 1 larger than current maximum - ## fibonacci. - push @fib, $fib[-2]+$fib[-1]; - $fib{$fib[-1]}=1; - } - next unless exists $fib{$ds}; - say $i; - $n--; + ## If we dont have a large enough fib add the next one... + ## Digit sum can only be 1 larger than current maximum + ## fibonacci. + ($fib{$fa+$fb},$fa,$fb)=(1,$fb,$fa+$fb) if $ds > $fb; + (say $i)**$n-- if exists $fib{$ds}; } |