Merge pull request #4597 from Util/branch-for-challenge-122

Add Raku and Perl solutions for #122 by Bruce Gray.

4 files changed, 80 insertions, 0 deletions

diff --git a/challenge-122/bruce-gray/perl/ch-1.pl b/challenge-122/bruce-gray/perl/ch-1.pl
new file mode 100644
index 0000000000..70beafbe8f
--- /dev/null
+++ b/challenge-122/bruce-gray/perl/ch-1.pl
@@ -0,0 +1,32 @@
+use strict;
+use warnings;
+use 5.020;
+use experimental qw<signatures>;
+
+sub make_arithmetic_generator ( $start, $increment ) {
+    my $last = $start - $increment;
+    return sub {
+        return ( $last += $increment );
+    };
+}
+sub running_average_generator ( $code_for_next_input ) {
+    my ($sum, $count);
+    return sub {
+        return ( $sum += $code_for_next_input->() ) / ++$count;
+    };
+}
+
+my $stream_next  = make_arithmetic_generator( 10, 10 );
+my $avg_next     = running_average_generator( $stream_next );
+my $count_wanted = 20;
+while ( defined( my $avg = $avg_next->() ) and $count_wanted-- ) {
+    say $avg;
+}
+
+# I would have just used this code,
+# but the task specifies "stream", not "list" or "array"!
+# sub running_average ( @s ) {
+#     my ( $sum, $count );
+#     return map { ($sum += $_) / ++$count } @s;
+# }
+# say for running_average( map { $_ * 10 } 1..20 );
diff --git a/challenge-122/bruce-gray/perl/ch-2.pl b/challenge-122/bruce-gray/perl/ch-2.pl
new file mode 100644
index 0000000000..f537de2105
--- /dev/null
+++ b/challenge-122/bruce-gray/perl/ch-2.pl
@@ -0,0 +1,20 @@
+use strict;
+use warnings;
+use 5.024;
+use experimental qw<signatures>;
+
+sub bball_ways ( $S ) {
+    use constant SHOT_VALUES => [ 1, 2, 3 ];
+    return [] if $S == 0;
+    return    if $S <  0;
+
+    my @ret;
+
+    for my $n ( SHOT_VALUES->@* ) {
+        push @ret, map [ $n, @{$_} ], bball_ways($S - $n);
+    }
+
+    return @ret;
+}
+
+say join(' ', @{$_}) for bball_ways( $ARGV[0] );
diff --git a/challenge-122/bruce-gray/raku/ch-1.raku b/challenge-122/bruce-gray/raku/ch-1.raku
new file mode 100644
index 0000000000..a96e47f57b
--- /dev/null
+++ b/challenge-122/bruce-gray/raku/ch-1.raku
@@ -0,0 +1,10 @@
+# sub ra { ( [\+] @^s ) Z/ ( 1 .. * ) }
+
+sub running_average ( @s ) {
+    constant @running_count = 1 .. *;
+    my       @running_sum   = [\+] @s;
+
+    return @running_sum Z/ @running_count;
+}
+
+put running_average( 10, 20 … * ).head(25);
diff --git a/challenge-122/bruce-gray/raku/ch-2.raku b/challenge-122/bruce-gray/raku/ch-2.raku
new file mode 100644
index 0000000000..e424a47ade
--- /dev/null
+++ b/challenge-122/bruce-gray/raku/ch-2.raku
@@ -0,0 +1,18 @@
+sub b'ball-ways ( UInt:D $S ) {
+    constant @SHOT_VALUES = 1, 2, 3;
+    return if $S == 0;
+
+    return gather for @SHOT_VALUES -> $n {
+        next if $S - $n < 0;
+
+        if b'ball-ways($S - $n) -> @ways {
+            take ($n, |.list)  for @ways;
+        }
+        else {
+            take ($n,);
+        }
+    }
+}
+
+unit sub MAIN ( UInt:D $final_score );
+.put for b'ball-ways(  $final_score );