Solve 122: Average of Stream & Basketball Points by E. Choroba

2 files changed, 112 insertions, 0 deletions

diff --git a/challenge-122/e-choroba/perl/ch-1.pl b/challenge-122/e-choroba/perl/ch-1.pl
new file mode 100755
index 0000000000..d7f574727d
--- /dev/null
+++ b/challenge-122/e-choroba/perl/ch-1.pl
@@ -0,0 +1,67 @@
+#!/usr/bin/perl
+use warnings;
+use strict;
+use feature qw{ say };
+
+# Stream is not an array. Stream is a source of values that can
+# produce new values infinitely.
+
+{   package Stream;
+    use Moo::Role;
+
+    requires qw{ first next_state };
+
+    has state => (is => 'rw', predicate => 1);
+    sub next_value {
+        my ($self) = @_;
+        $self->state($self->has_state
+                     ? $self->next_state($self->state) : $self->first);
+        return $self->value
+    }
+    sub value { $_[0]->state }
+}
+
+{   package Stream::Sequence::Arithmetic;
+    use Moo::Role;
+    use MooX::Role::Parameterized;
+
+    with 'Stream';
+    role {
+        my ($params, $mop) = @_;
+        $mop->method(first      => sub { $params->{first} });
+        $mop->method(next_state => sub { $_[1] + $params->{difference} });
+    };
+}
+
+{   package Stream::TenPlusTen;
+    use Moo;
+
+    'Stream::Sequence::Arithmetic'->apply({first      => 10,
+                                           difference => 10});
+}
+
+{   package Stream::Fibonacci;
+    use Moo;
+    with 'Stream';
+
+    sub first      { [0, 1] }
+    sub next_state { [$_[1][1], $_[1][0] + $_[1][1]] }
+
+    around value => sub { $_[1]->state->[-1] }
+}
+
+sub stream_average {
+    my ($stream, $count) = @_;
+    my $sum = 0;
+    for my $tally (1 .. $count) {
+        my $n = $stream->next_value;
+        $sum += $n;
+        say $tally, "\t$n\t$sum / $tally\t", $sum / $tally;
+    }
+}
+
+say '10 + 10';
+stream_average('Stream::TenPlusTen'->new(), 10);
+
+say 'Fibonacci';
+stream_average('Stream::Fibonacci'->new(), 10);
diff --git a/challenge-122/e-choroba/perl/ch-2.pl b/challenge-122/e-choroba/perl/ch-2.pl
new file mode 100755
index 0000000000..96351f085e
--- /dev/null
+++ b/challenge-122/e-choroba/perl/ch-2.pl
@@ -0,0 +1,45 @@
+#!/usr/bin/perl
+use warnings;
+use strict;
+
+sub basketball_points {
+    my ($score) = @_;
+    return [] if 0 == $score;
+
+    my @result;
+    for my $shot (grep $_ <= $score, 1, 2, 3) {
+        push @result, map [$shot, @$_], basketball_points($score - $shot);
+    }
+    return @result
+}
+
+use Test2::V0;
+plan 2;
+
+is [basketball_points(4)], bag {
+    item [1, 1, 1, 1];
+    item [1, 1, 2];
+    item [1, 2,  1];
+    item [1, 3];
+    item [2, 1, 1];
+    item [2, 2];
+    item [3, 1];
+    end
+};
+
+is [basketball_points(5)], bag {
+    item [1, 1, 1, 1, 1];
+    item [1, 1, 1, 2];
+    item [1, 1, 2, 1];
+    item [1, 1, 3];
+    item [1, 2, 1, 1];
+    item [1, 2, 2];
+    item [1, 3, 1];
+    item [2, 1, 1, 1];
+    item [2, 1, 2];
+    item [2, 2, 1];
+    item [2, 3];
+    item [3, 1, 1];
+    item [3, 2];
+    end
+};