exercism-perl5

commit db7a0fc31bc421b402bcc3eb622a85b8a114c48e
parent 92f5a893bac520226d181a32cffe5210ec2003ef
Author: Samir Parikh <noreply@samirparikh.com>
Date:   Sun, 27 Feb 2022 18:25:24 +0000

get all tests to pass for Pascal's triangle

Diffstat:
M
pascals-triangle/PascalsTriangle.pm
 | 
17
++++++++++++++++-

1 file changed, 16 insertions(+), 1 deletion(-)
diff --git a/pascals-triangle/PascalsTriangle.pm b/pascals-triangle/PascalsTriangle.pm
@@ -6,7 +6,22 @@ our @EXPORT_OK = qw<pascal_rows>;
 
 sub pascal_rows {
   my ($rows) = @_;
-  return undef;
+  my $output = '';
+  my @triangle = ();
+  return $output unless $rows;
+  return '1' if ( $rows == 1 );
+  push @triangle => [ 1 ];
+  foreach my $r ( 2 .. $rows) {
+      my @row = ();
+      foreach my $element ( 1 .. $r ) {
+          my $p1 = $element == 1  ? 0 : $triangle[$r-2][$element-2];
+          my $p2 = $element == $r ? 0 : $triangle[$r-2][$element-1];
+          push @row => $p1 + $p2; 
+      }
+      push @triangle => \@row;
+  }
+  $output = join( "\n", map { join ' ', @$_ } @triangle );
+  return $output;
 }
 
 1;