diff options
| -rwxr-xr-x | challenge-060/jo-37/perl/ch-2.pl | 50 |
1 files changed, 29 insertions, 21 deletions
diff --git a/challenge-060/jo-37/perl/ch-2.pl b/challenge-060/jo-37/perl/ch-2.pl index 9ef127aae8..e9da2dcdbf 100755 --- a/challenge-060/jo-37/perl/ch-2.pl +++ b/challenge-060/jo-37/perl/ch-2.pl @@ -7,7 +7,9 @@ use Test2::V0; -# expects a number of the desired length and a control hash. +# check_num expects: +# - number that has the desired length +# - control hash. # if the number fits, it is added to the result set. # cut this branch otherwise sub check_num { @@ -19,16 +21,18 @@ sub check_num { 0; } -# recursively constructs numbers from the given parts. -# expects the current recursion level and the config hash as parameters -sub gennum; -sub gennum { +# Recursively constructs numbers from the given parts. +# gen_num expects: +# - current recursion level +# - config hash +sub gen_num; +sub gen_num { my $level = shift; my $ctl = shift; our @current; - # make the array element for the current level local to this - # invocation, thus auto-deleting it at return + # localize the array element for the current level, + # will be auto-deleted at return local $current[$level]; # loop over parts at this level @@ -48,20 +52,21 @@ sub gennum { return; } else { # recurse to next level - gennum $level + 1, $ctl; + gen_num $level + 1, $ctl; } } elsif ($t == 0) { # $value has desired length # cut if $value is too large + # next cannot lead to something smaller, + # even if it is shorter return unless check_num $value, $ctl; - } else { # $value is too long - return; } + # else: $value is too long, next might be shorter } } -# create numbers of given length, below given limit -# and assembled from given parts -# parts are not restricted to single digits +# Create numbers of given length, below given limit +# and assembled from given parts. +# Parts are not restricted to single digits. sub create_numbers { my $length = shift; my $limit = shift; @@ -72,20 +77,23 @@ sub create_numbers { my $ctl = {length => $length, limit => $limit, parts => $parts}; # enter generator - gennum 0, $ctl; + gen_num 0, $ctl; return sort keys %{$ctl->{result}}; } -my @L = (0, 1, 2, 5); -my $X = 2; -my $Y = 21; -my @result = create_numbers $X, $Y, @L; -is \@result, [10, 11, 12, 15, 20], 'example from challenge'; +# main +my (@L, $X, $Y, @R); + +@L = (0, 1, 2, 5); +$X = 2; +$Y = 21; +@R = create_numbers $X, $Y, @L; +is \@R, [10, 11, 12, 15, 20], 'example from challenge'; @L = (0, 1, 100000002); $X = 9; $Y = 100000003; -@result = create_numbers $X, $Y, @L; -is \@result, [100000000, 100000001, 100000002], 'cut search space example'; +@R = create_numbers $X, $Y, @L; +is \@R, [100000000, 100000001, 100000002], 'cut example'; done_testing; |