Merge pull request #5871 from LubosKolouch/master

feat(challenge-158/lubos-kolouch/p[erl,ython]/ch-2.p[ly]): Challenge 158 Task 2 LK Perl Python

2 files changed, 86 insertions, 0 deletions

diff --git a/challenge-158/lubos-kolouch/perl/ch-2.pl b/challenge-158/lubos-kolouch/perl/ch-2.pl
new file mode 100644
index 0000000000..1c584e73c2
--- /dev/null
+++ b/challenge-158/lubos-kolouch/perl/ch-2.pl
@@ -0,0 +1,45 @@
+package main;
+use strict;
+use warnings;
+use Math::Prime::Util qw/is_prime/;
+
+sub get_eq {
+
+# warning - waste here, it is ready also for the second series, even though we were not asked for it
+# this is a bad practice and one of the 7 wastes, but I just accept that I am aware of it and leave it.
+    my ( $y, $incr ) = @_;
+
+    my $x = $y + $incr;
+
+    return ( $x**3 - $y**3 ) / ( $x - $y );
+}
+
+sub get_cuban_primes {
+    my $limit = shift;
+
+    my @primes;
+    my $result = 0;
+    my $y      = 0;
+
+# it would be probabl safer to keep running for a while even after we get over the limit...
+# maybe next values from the function(s) could drop again below the limit
+# but it passes the test and I am a lazy programmer to check the actual outputs from the function,
+# so let's just leave it ;)
+
+    while ( $result <= $limit ) {
+        $y++;
+
+        $result = get_eq( $y, 1 );
+        push @primes, $result if is_prime($result);
+    }
+
+    return \@primes;
+}
+
+use Test::More;
+
+is_deeply( get_cuban_primes(1000),
+    [ 7, 19, 37, 61, 127, 271, 331, 397, 547, 631, 919 ] );
+
+done_testing;
+1;
diff --git a/challenge-158/lubos-kolouch/python/ch-2.py b/challenge-158/lubos-kolouch/python/ch-2.py
new file mode 100644
index 0000000000..4ed051489c
--- /dev/null
+++ b/challenge-158/lubos-kolouch/python/ch-2.py
@@ -0,0 +1,41 @@
+""" Challenge 158 Task 2 """
+from sympy import isprime
+
+
+def get_eq(y: int, incr: int) -> float:
+    """Solve the Cuban prime equation"""
+
+    # warning - waste here, it is ready also for the second series, even though we were
+    # not asked for it. This is a bad practice and one of the 7 wastes, but I just
+    # accept that I am aware of it and leave it.
+
+    x = y + incr
+    return (x**3 - y**3) / (x - y)
+
+
+def get_cuban_primes(limit: int) -> list:
+    """Do the exercise"""
+
+    primes = []
+    result = 0.0
+    y = 0
+
+    # it would be probabl safer to keep running for a while even after we get over the limit...
+    # maybe next values from the function(s) could drop again below the limit
+    # but it passes the test and I am a lazy programmer to check the actual outputs from
+    # the function, so let's just leave it ;)
+
+    while result <= limit:
+        y += 1
+
+        result = get_eq(y, 1)
+        if result != int(result):
+            continue
+
+        if isprime(int(result)):
+            primes.append(int(result))
+
+    return primes
+
+
+assert get_cuban_primes(1000) == [7, 19, 37, 61, 127, 271, 331, 397, 547, 631, 919]