Merge pull request #3256 from pauloscustodio/008

Add Perl solution to challenge 008

4 files changed, 91 insertions, 0 deletions

diff --git a/challenge-008/paulo-custodio/README b/challenge-008/paulo-custodio/README
new file mode 100644
index 0000000000..87dc0b2fbd
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+++ b/challenge-008/paulo-custodio/README
@@ -0,0 +1 @@
+Solution by Paulo Custodio
diff --git a/challenge-008/paulo-custodio/perl/ch-1.pl b/challenge-008/paulo-custodio/perl/ch-1.pl
new file mode 100644
index 0000000000..cde823ccf9
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+++ b/challenge-008/paulo-custodio/perl/ch-1.pl
@@ -0,0 +1,34 @@
+#!/usr/bin/env perl
+
+# Challenge 008
+#
+# Challenge #1
+# Write a script that computes the first five perfect numbers. A perfect number
+# is an integer that is the sum of its positive proper divisors (all divisors
+# except itself). Please check Wiki for more information. This challenge was
+# proposed by Laurent Rosenfeld.
+
+use strict;
+use warnings;
+use 5.030;
+use Math::Prime::Util 'next_prime', 'is_prime';
+
+# Euclid proved that 2^(p−1)*(2^p − 1) is an even perfect number 
+# whenever 2p − 1 is prime 
+sub perfect_iter {
+	my $p = 1;
+	return sub {
+		while (1) {
+			$p = next_prime($p); 	# next prime number
+			my $f = (2**$p)-1;
+			return (2**($p-1))*$f if is_prime($f);
+		}
+	};
+}
+
+
+my $n = shift || 5;
+my $iter = perfect_iter();
+for (1..$n) {
+	say $iter->();
+}
diff --git a/challenge-008/paulo-custodio/perl/ch-2.pl b/challenge-008/paulo-custodio/perl/ch-2.pl
new file mode 100644
index 0000000000..840e002f18
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+++ b/challenge-008/paulo-custodio/perl/ch-2.pl
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+#!/usr/bin/env perl
+
+# Challenge 008
+#
+# Challenge #2
+# Write a function, ‘center’, whose argument is a list of strings, which will
+# be lines of text. The function should insert spaces at the beginning of the
+# lines of text so that if they were printed, the text would be centered, and
+# return the modified lines.
+
+use strict;
+use warnings;
+use 5.030;
+use List::Util 'max';
+
+sub center {
+	my(@lines) = @_;
+	my $max_len = max(map {length($_)} @lines);
+	@lines = map {$_ = " " x (($max_len-length($_))/2) . $_} @lines;
+	return @lines;
+}
+
+my @lines = center(@ARGV);
+say join "\n", @lines;
diff --git a/challenge-008/paulo-custodio/test.pl b/challenge-008/paulo-custodio/test.pl
new file mode 100644
index 0000000000..f4ebb29f9f
--- /dev/null
+++ b/challenge-008/paulo-custodio/test.pl
@@ -0,0 +1,32 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use 5.030;
+use Test::More;
+
+is capture("perl perl/ch-1.pl 5"), <<END;
+6
+28
+496
+8128
+33550336
+END
+
+is capture("perl perl/ch-2.pl 'This' 'is' 'a test of the' 'center function'"), <<END;
+     This
+      is
+ a test of the
+center function
+END
+
+done_testing;
+
+
+sub capture {
+	my($cmd) = @_;
+	my $out = `$cmd`;
+	$out =~ s/[ \r\t]*\n/\n/g;
+	return $out;
+}
+