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| -rw-r--r-- | challenge-147/steven-wilson/perl/ch-01.pl | 39 |
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 --- /dev/null +++ b/challenge-147/steven-wilson/perl/ch-01.pl @@ -0,0 +1,39 @@ +#!/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; |
