Jorts!

3 files changed, 86 insertions, 0 deletions

diff --git a/challenge-139/dave-jacoby/blog.txt b/challenge-139/dave-jacoby/blog.txt
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+https://jacoby.github.io/2021/11/15/its-the-mullet-of-algorithms-the-weekly-challenge-139.html
\ No newline at end of file
diff --git a/challenge-139/dave-jacoby/perl/ch-1.pl b/challenge-139/dave-jacoby/perl/ch-1.pl
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+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use feature qw{ say state postderef signatures };
+no warnings qw{ experimental };
+
+# JortSort - https://jort.technology/ - https://github.com/jennschiffer/jortsort
+
+my @examples;
+push @examples, [ 1 .. 5 ];
+push @examples, [ 1, 3, 2, 4, 5 ];
+push @examples, [ 1 .. 20 ];
+push @examples, [ sort { rand 1 <=> rand 1 } 1 .. 20 ];
+
+for my $input (@examples) {
+    my $o = jortsort( $input->@* );
+    my $i = join ',',$input->@*;
+    say <<"END";
+    Input: \@n = ($i)
+    Output: $o
+END
+}
+
+# basically? It's sorted already, or go back and try again.
+sub jortsort (@array ) {
+    my @copy = sort { $a <=> $b } @array;
+    for my $i ( 0 .. -1 + scalar @array ) {
+        return 0 if $copy[$i] ne $array[$i];
+    }
+    return 1;
+}
diff --git a/challenge-139/dave-jacoby/perl/ch-2.pl b/challenge-139/dave-jacoby/perl/ch-2.pl
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+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use feature qw{ say postderef signatures state };
+no warnings qw{ experimental };
+
+# https://en.wikipedia.org/wiki/Full_reptend_prime
+
+#  The first five long primes are: 7, 17, 19, 23, 29
+
+use Math::BigFloat;
+Math::BigFloat->accuracy(200);
+my @long_primes;
+for my $i ( 1 .. 50 ) {
+    next unless is_long_prime($i);
+    push @long_primes, $i;
+}
+say 'The first five Long Primes are: ', join ', ', @long_primes;
+
+sub is_long_prime ($n ) {
+    Math::BigFloat->accuracy($n*3);
+    return 0 unless is_prime($n);
+    my $bign = Math::BigFloat->new($n);
+    my $big1 = Math::BigFloat->new(1);
+    my $big  = $big1->bdiv($bign);
+    $big =~ s/0+$//mix;
+    my $alt = $big;
+    $alt =~ s/^0\.//;
+
+    my $l = $n - 1;
+    for my $i ( 1 .. $l ) {
+        my ( $f1, $f2 ) = $alt =~ m{(\d{$i})}g;
+        return 0 if !defined $f2;
+        return 0 if $f1 == $f2 && $i < $l;
+        return 0 if $f1 != $f2 && $i == $l;
+    }
+
+    return 1;
+}
+
+sub is_prime ( $n ) {
+    my @factors = factor($n);
+    return scalar @factors == 1 ? 1 : 0;
+}
+
+sub factor ( $n ) {
+    my @factors;
+    for my $i ( 1 .. $n - 1 ) {
+        push @factors, $i if $n % $i == 0;
+    }
+    return @factors;
+}