package KindergartenGarden;
use strict;
use warnings;
use Exporter qw<import>;
use Data::Dumper;
our @EXPORT_OK = qw<plants>;

sub plants {
  # $input is a reference to a hash with two keys: diagram and student
  # both diagram and student are scalar strings
  my ($input) = @_;
  my $diagram = $input->{diagram};
  my $student = $input->{student};
  my @rows = split /\n/, $diagram;
  my @children = qw( Alice Bob Charlie David Eve Fred Ginny Harriet Ileana Joseph Kincaid Larry);
  my @positions = map { $_ * 2 } (0 .. scalar(@children) - 1);
  my %child_pos;
  @child_pos{ @children } = @positions; # hash slice
  my %plants = qw( G grass C clover R radishes V violets);
  my @student_plants;
  foreach (@rows) {
      push @student_plants, $plants{substr($_, $child_pos{$student}, 1)};
      push @student_plants, $plants{substr($_, $child_pos{$student} + 1, 1)};
  }
  return \@student_plants;
}

1;