Added challenge 200-1.

1 files changed, 47 insertions, 3 deletions

diff --git a/challenge-200/robbie-hatley/perl/ch-1.pl b/challenge-200/robbie-hatley/perl/ch-1.pl
index 2d69624d72..789427c264 100755
--- a/challenge-200/robbie-hatley/perl/ch-1.pl
+++ b/challenge-200/robbie-hatley/perl/ch-1.pl
@@ -15,15 +15,59 @@ Example 2:  Input: @array = (2)        Output: () as no slice found.
 
 =cut
 
+# IO NOTES:
+#
 # NOTE: Input is by either built-in array of arrays, or by @ARGV. If using
 #       @ARGV, input should be a space-separated list of integers, which will
 #       be interpreted as a single array.
-
+#
 # NOTE: Output is to stdout and will be a list of all arithmetic slice for
 #       each input array.
 
 # PRELIMINARIES:
 use v5.36;
+$,=" ";
+
+# SUBROUTINES:
+
+sub is_arith($slice_ref){
+   my @slice = @{$slice_ref};
+   my $size = scalar @slice;
+   if ( $size < 3 ) {return 0;}
+   my $init = $slice[1]-$slice[0];
+   for ( my $idx = 2 ; $idx <= $#slice ; ++$idx ){
+      if ($slice[$idx] - $slice[$idx-1] != $init) {return 0}}
+   return 1;}
+
+sub get_arith_slices($array_ref){
+   my @array = @{$array_ref};
+   my @slices = ();
+   my @arith_slices = ();
+   my $size = scalar @array;
+   my @masks = (0..((2**$size)-1));
+   foreach my $mask (@masks){
+      my @slice = ();
+      for ( my $idx = 0 ; $idx <= $#array ; ++$idx ){
+         my $yesno = ($mask/2**($size-$idx-1))%2;
+         if ($yesno) {push @slice, $array[$idx]}}
+      push @slices, \@slice;}
+   foreach my $slice_ref (@slices){
+      if (is_arith($slice_ref)) {push @arith_slices, $slice_ref}}
+   return @arith_slices;}
+
+# DEFAULT INPUT:
+my @arrays = ([1,2,3,4],[2]);
+
+# NON-DEFAULT INPUT:
+if (@ARGV) {@arrays = ([@ARGV])}
 
-say "Sorry, this is just a stub; ran out of time.";
-say "\"Task 2\", however, is fully functional.";
+# MAIN BODY OF SCRIPT:
+for (@arrays){
+   my $array_ref = $_;
+   my @array = @{$array_ref};
+   my @arith_slices = get_arith_slices($array_ref);
+   my $num_arith_slices = scalar @arith_slices;
+   say '';
+   say "Array = (@array)";
+   say "Found $num_arith_slices arithmetic slices:";
+   for (@arith_slices) {my @slice=@{$_}; say "(@slice)";}}
\ No newline at end of file