Merge pull request #5518 from oWnOIzRi/week147

add solution week 147 task 1 in perl

1 files changed, 39 insertions, 0 deletions

diff --git a/challenge-147/steven-wilson/perl/ch-01.pl b/challenge-147/steven-wilson/perl/ch-01.pl
new file mode 100644
index 0000000000..ceefab2a3d
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+++ b/challenge-147/steven-wilson/perl/ch-01.pl
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+#!/usr/bin/env perl
+# Week 147 Task 1
+# Truncatable Prime
+# Write a script to generate first 20 left-truncatable prime numbers in base 10.
+
+use strict;
+use warnings;
+use feature qw/ say /;
+use Math::Prime::Util qw/ next_prime is_prime /;
+
+my @ltp          = qw/ 2 /;
+my $prime_number = 2;
+
+while ( scalar @ltp < 20 ) {
+    $prime_number = next_prime($prime_number);
+    if ( is_truncatable_prime($prime_number) ) {
+        push @ltp, $prime_number;
+    }
+}
+
+sub is_truncatable_prime {
+    my $prime_number   = shift;
+    my $truncatable    = 1;
+    while ( length $prime_number > 0 ) {
+        if ( $prime_number =~ /0/ ) {    # contains no 0
+            $truncatable = 0;
+            last;
+        }
+        if ( not is_prime($prime_number) ) {
+            $truncatable = 0;
+            last;
+        }
+        $prime_number =~ /^[0-9]{1}([0-9]*)/;
+        $prime_number = $1;
+    }
+    return $truncatable;
+}
+
+say join " ", @ltp;