Initial commit with BinaryGap solution

lib/BinaryGap.pm

@@ -0,0 +1,64 @@
+package BinaryGap;
+use Modern::Perl;
+# use List::MoreUtils qw(first_index); # codility does not have
+use List::Util qw(max first);
+
+use Data::Dumper;
+
+
+sub solution {
+   # N is an integer within the range [1..2,147,483,647]
+   my ($N) = @_;
+   my $max_gap = 0;
+   # Make sure number is in acceptable range, if not return 0
+   if (($N < 1) || ($N > '2147483647')) {
+      return $max_gap;
+   }
+   # convert integer to binary
+   my $bin_num = unpack("B*", pack("N", $N));
+
+   # convert to array
+   my @bin_array = split('',$bin_num);
+
+   # find first 1. If there is not one, return for performance
+   my $first_index;
+   for (0 .. $#bin_array) {
+      if ($bin_array[$_] == 1) {
+         $first_index = $_;
+         last;
+      }
+   }
+   return $max_gap unless $first_index;
+
+   # If there are less than two 1s in the array, return 0
+   my $ones_total_count = grep { $_ == 1  } @bin_array;
+   if ($ones_total_count < 2) {
+      return $max_gap;
+   }
+
+   # If there is just one 0 in the array, return 0
+   my $zeros_total_count = grep { $_ == 0  } @bin_array;
+   if ($zeros_total_count < 2) {
+      return $max_gap;
+   }
+
+   # Get all 1 indexes
+   my @i = grep { $bin_array[$_] == 1 } 0 .. $#bin_array;
+   my $last_index = $i[$#i];
+
+   my $zero_count = 0;
+   for my $index ($first_index .. $last_index) {
+      my $num = $bin_array[$index];
+      if ($num == 1) {
+         $zero_count = 0;
+      }
+      else {
+         $zero_count++;
+         $max_gap = max($zero_count, $max_gap);
+      }
+   }
+
+   return $max_gap;
+}
+
+1;