Add Perl solution

6 files changed, 161 insertions, 11 deletions

diff --git a/challenge-167/paulo-custodio/perl/ch-1.pl b/challenge-167/paulo-custodio/perl/ch-1.pl
index 92dff3782f..6ee40c97f8 100644
--- a/challenge-167/paulo-custodio/perl/ch-1.pl
+++ b/challenge-167/paulo-custodio/perl/ch-1.pl
@@ -64,11 +64,10 @@ sub next_circular_prime {
     return $n;
 }
 
-@ARGV or die "usage: ch-1.pl n\n";
+@ARGV==1 or die "usage: ch-1.pl n\n";
 my $n=shift;
 my @cprimes;
 my $cp=1;
-my %seen;
 while (@cprimes<$n) {
     $cp=next_circular_prime($cp);
     push @cprimes,$cp if $cp>=100;
diff --git a/challenge-167/paulo-custodio/perl/ch-2.pl b/challenge-167/paulo-custodio/perl/ch-2.pl
index 180fbfdc48..65e303772e 100644
--- a/challenge-167/paulo-custodio/perl/ch-2.pl
+++ b/challenge-167/paulo-custodio/perl/ch-2.pl
@@ -26,15 +26,15 @@ use List::Util 'sum';
 
 use constant g => 7;
 my @p = (
-    0.99999999999980993,
-    676.5203681218851,
-    -1259.1392167224028,
-    771.32342877765313,
-    -176.61502916214059,
-    12.507343278686905,
-    -0.13857109526572012,
-    9.9843695780195716e-6,
-    1.5056327351493116e-7
+     0.99999999999980993227684700473478,
+   676.520368121885098567009190444019,
+ -1259.13921672240287047156078755283,
+   771.3234287776530788486528258894,
+  -176.61502916214059906584551354,
+    12.507343278686904814458936853,
+    -0.13857109526572011689554707,
+     9.984369578019570859563e-6,
+     1.50563273514931155834e-7
 );
 
 use constant EPSILON => 1e-07;
diff --git a/challenge-168/paulo-custodio/perl/ch-1.pl b/challenge-168/paulo-custodio/perl/ch-1.pl
new file mode 100644
index 0000000000..eda2430282
--- /dev/null
+++ b/challenge-168/paulo-custodio/perl/ch-1.pl
@@ -0,0 +1,56 @@
+#!/usr/bin/perl
+
+# Challenge 168
+#
+# Task 1: Perrin Prime
+# Submitted by: Roger Bell_West
+#
+# The Perrin sequence is defined to start with [3, 0, 2]; after that, term N is
+# the sum of terms N-2 and N-3. (So it continues 3, 2, 5, 5, 7, ….)
+#
+#     A Perrin prime is a number in the Perrin sequence which is also a prime
+#     number.
+#
+# Calculate the first 13 Perrin Primes.
+#
+# f(13) = [2, 3, 5, 7, 17, 29, 277, 367, 853, 14197, 43721, 1442968193,
+#          792606555396977]
+
+use Modern::Perl;
+
+sub is_prime {
+    my($n) = @_;
+    return 0 if $n <= 1;
+    return 1 if $n <= 3;
+    return 0 if ($n % 2)==0 || ($n % 3)==0;
+    for (my $i = 5; $i*$i <= $n; $i += 6) {
+        return 0 if ($n % $i)==0 || ($n % ($i+2))==0;
+    }
+    return 1;
+}
+
+sub perrin_seq {
+    my(@t)=(3,0,2);
+    return sub {
+        push @t, $t[-2]+$t[-3];
+        return shift @t;
+    }
+}
+
+sub perrin_prime_seq {
+    my $it=perrin_seq();
+    my %seen;
+    return sub {
+        while (1) {
+            my $n=$it->();
+            return $n if is_prime($n) && !$seen{$n}++;
+        }
+    };
+}
+
+@ARGV==1 or die "usage: ch-1.pl n\n";
+my $n=shift;
+my @pp;
+my $it=perrin_prime_seq();
+push @pp, $it->() while @pp<$n;
+say join ", ", sort {$a<=>$b} @pp;
diff --git a/challenge-168/paulo-custodio/perl/ch-2.pl b/challenge-168/paulo-custodio/perl/ch-2.pl
new file mode 100644
index 0000000000..b3ce77932c
--- /dev/null
+++ b/challenge-168/paulo-custodio/perl/ch-2.pl
@@ -0,0 +1,65 @@
+#!/usr/bin/perl
+
+# Challenge 168
+#
+# Task 2: Home Prime
+# Submitted by: Mohammad S Anwar
+#
+# You are given an integer greater than 1.
+#
+# Write a script to find the home prime of the given number.
+#
+# In number theory, the home prime HP(n) of an integer n greater than 1 is the
+# prime number obtained by repeatedly factoring the increasing concatenation of
+# prime factors including repetitions.
+#
+# Further information can be found on Wikipedia and OEIS.
+# Example
+#
+# As given in the Wikipedia page,
+#
+# HP(10) = 773, as 10 factors as 2×5 yielding HP10(1) = 25, 25 factors as 5×5
+# yielding HP10(2) = HP25(1) = 55, 55 = 5×11 implies HP10(3) = HP25(2) = HP55(1)
+# = 511, and 511 = 7×73 gives HP10(4) = HP25(3) = HP55(2) = HP511(1) = 773, a
+# prime number.
+
+use Modern::Perl;
+
+sub is_prime {
+    my($n) = @_;
+    return 0 if $n <= 1;
+    return 1 if $n <= 3;
+    return 0 if ($n % 2)==0 || ($n % 3)==0;
+    for (my $i = 5; $i*$i <= $n; $i += 6) {
+        return 0 if ($n % $i)==0 || ($n % ($i+2))==0;
+    }
+    return 1;
+}
+
+sub prime_factors {
+    my($n) = @_;
+    my @factors;
+    my $p = 0;
+    while ($n > 1) {
+        do { $p++; } while (!is_prime($p));
+        while ($n % $p == 0) {
+            push @factors, $p;
+            $n /= $p;
+        }
+    }
+    return @factors;
+}
+
+sub home_prime {
+    my($n) = @_;
+    die unless $n > 1;
+    while (!is_prime($n)) {
+        my @factors = prime_factors($n);
+        $n = 0+join '', @factors;
+    }
+    return $n;
+}
+
+
+@ARGV==1 or die "usage: ch-1.pl n\n";
+say home_prime(shift);
diff --git a/challenge-168/paulo-custodio/t/test-1.yaml b/challenge-168/paulo-custodio/t/test-1.yaml
new file mode 100644
index 0000000000..03e75b6351
--- /dev/null
+++ b/challenge-168/paulo-custodio/t/test-1.yaml
@@ -0,0 +1,5 @@
+- setup:
+  cleanup:
+  args:     13
+  input:
+  output:   2, 3, 5, 7, 17, 29, 277, 367, 853, 14197, 43721, 1442968193, 792606555396977
diff --git a/challenge-168/paulo-custodio/t/test-2.yaml b/challenge-168/paulo-custodio/t/test-2.yaml
new file mode 100644
index 0000000000..65e1ee34d9
--- /dev/null
+++ b/challenge-168/paulo-custodio/t/test-2.yaml
@@ -0,0 +1,25 @@
+- setup:
+  cleanup:
+  args:     2
+  input:
+  output:   2
+- setup:
+  cleanup:
+  args:     4
+  input:
+  output:   211
+- setup:
+  cleanup:
+  args:     6
+  input:
+  output:   23
+- setup:
+  cleanup:
+  args:     9
+  input:
+  output:   311
+- setup:
+  cleanup:
+  args:     10
+  input:
+  output:   773