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-rw-r--r--challenge-147/steven-wilson/perl/ch-01.pl39
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diff --git a/challenge-147/steven-wilson/perl/ch-01.pl 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;