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| -rw-r--r-- | challenge-167/lubos-kolouch/perl/ch-1.pl | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/challenge-167/lubos-kolouch/perl/ch-1.pl b/challenge-167/lubos-kolouch/perl/ch-1.pl new file mode 100644 index 0000000000..97c2199d8e --- /dev/null +++ b/challenge-167/lubos-kolouch/perl/ch-1.pl @@ -0,0 +1,52 @@ +use strict; +use warnings; +use Math::Prime::Util qw(is_prime next_prime); + +sub is_circular_prime { + my $prime = shift; + + my $digits = length($prime); + + for my $i ( 0 .. $digits - 1 ) { + return 0 unless is_prime($prime); + my $digit = substr( $prime, 0, 1 ); + $prime = substr( $prime, 1, $digits - 1 ) . $digit; + } + + return 1; +} + +sub generate_primes { + my $limit = shift; + + my @primes; + my $prime = next_prime(100); + + while ( scalar @primes < $limit ) { + push @primes, $prime if is_circular_prime($prime); + $prime = next_prime($prime); + } + + return \@primes; +} + +use Test::More; + +is( is_circular_prime(2), 1, '2 is a circular prime' ); +is( is_circular_prime(3), 1, '3 is a circular prime' ); +is( is_circular_prime(11), 1, '11 is a circular prime' ); +is( is_circular_prime(13), 1, '13 is a circular prime' ); +is( is_circular_prime(57), 0, '57 not a circular prime' ); +is( is_circular_prime(197), 1, '197 is a circular prime' ); + +# Note that the example given on the challenge is wrong according to +# https://oeis.org/A068652 + +is_deeply( + generate_primes(10), + [ 113, 131, 197, 199, 311, 337, 373, 719, 733, 919 ], + + 'Generate primes' +); + +done_testing(); |