diff options
Diffstat (limited to 'challenge-109')
| -rw-r--r-- | challenge-109/dave-jacoby/blog.txt | 1 | ||||
| -rw-r--r-- | challenge-109/dave-jacoby/node/ch-1.js | 17 | ||||
| -rw-r--r-- | challenge-109/dave-jacoby/perl/ch-1.pl | 35 | ||||
| -rw-r--r-- | challenge-109/dave-jacoby/perl/ch-2.pl | 79 |
4 files changed, 132 insertions, 0 deletions
diff --git a/challenge-109/dave-jacoby/blog.txt b/challenge-109/dave-jacoby/blog.txt new file mode 100644 index 0000000000..98a826c8ac --- /dev/null +++ b/challenge-109/dave-jacoby/blog.txt @@ -0,0 +1 @@ +https://jacoby.github.io/2021/04/21/iterations-and-permutations-perl-weekly-challenge-109.html
\ No newline at end of file diff --git a/challenge-109/dave-jacoby/node/ch-1.js b/challenge-109/dave-jacoby/node/ch-1.js new file mode 100644 index 0000000000..72452fdcb5 --- /dev/null +++ b/challenge-109/dave-jacoby/node/ch-1.js @@ -0,0 +1,17 @@ +"use strict"; + +let list = Array(20) + .fill() + .map((x, i) => i + 1) + .map((x) => chowla(x)); +console.log(list.join(", ")); + +function chowla(n) { + return Array(n) + .fill() + .map((x, i) => i + 1) + .filter((x) => x != 1) + .filter((x) => x != n) + .filter((x) => n % x == 0) + .reduce((a, v) => a + v, 0); +} diff --git a/challenge-109/dave-jacoby/perl/ch-1.pl b/challenge-109/dave-jacoby/perl/ch-1.pl new file mode 100644 index 0000000000..96de494c1a --- /dev/null +++ b/challenge-109/dave-jacoby/perl/ch-1.pl @@ -0,0 +1,35 @@ +#!/usr/bin/env perl + +use strict; +use warnings; +use feature qw{ postderef say signatures state }; +no warnings qw{ experimental }; + +use List::Util qw{sum0}; + +my @test = ( 0, 0, 0, 2, 0, 5, 0, 6, 3, 7, 0, 15, 0, 9, 8, 14, 0, 20, 0, 21 ); + +say join ', ', @test; +say join ', ', map { chowla($_) } 1 .. 20; +say join ', ', map { chowla2($_) } 1 .. 20; + +# the old-fashioned for-loop way +sub chowla ( $n ) { + my $c = 0; + for my $i ( 1 .. $n ) { + my $m = $n % $i; + next if $i == 1 || $i == $n; + $c += $i if $m == 0; + } + return $c; +} + +# the new, hot functional approach +# using sum0 because if given an empty list, +# sum0 returns zero instead of undef +sub chowla2 ( $n ) { + return sum0 + grep { $n % $_ == 0 } + grep { $_ != 1 } + grep { $_ != $n } 1 .. $n; +} diff --git a/challenge-109/dave-jacoby/perl/ch-2.pl b/challenge-109/dave-jacoby/perl/ch-2.pl new file mode 100644 index 0000000000..d1dba3614c --- /dev/null +++ b/challenge-109/dave-jacoby/perl/ch-2.pl @@ -0,0 +1,79 @@ +#!/usr/bin/env perl + +use strict; +use warnings; +use feature qw{ postderef say signatures state }; +no warnings qw{ experimental }; + +use Algorithm::Permute; + +my $map = <<'END'; + (1) (3) + ╔══════════════╗ ╔══════════════╗ + ║ ║ ║ ║ + ║ a ║ ║ e ║ + ║ ║ (2) ║ ║ (4) + ║ ┌───╫──────╫───┐ ┌───╫─────────┐ + ║ │ ║ ║ │ │ ║ │ + ║ │ b ║ ║ d │ │ f ║ │ + ║ │ ║ ║ │ │ ║ │ + ║ │ ║ ║ │ │ ║ │ + ╚══════════╪═══╝ ╚═══╪══════╪═══╝ │ + │ c │ │ g │ + │ │ │ │ + │ │ │ │ + └──────────────┘ └─────────────┘ +END + +four_squares( 1 .. 7 ); + +sub four_squares ( @array ) { + my $array = join ', ', @array; + my $ap = Algorithm::Permute->new( \@array ); + while ( my @perm = $ap->next ) { + my $b1 = _box_1(@perm); + my $b2 = _box_2(@perm); + next if $b1 != $b2; + my $b3 = _box_3(@perm); + next if $b1 != $b3; + my $b4 = _box_4(@perm); + next if $b1 != $b4; + + my $a = $perm[0]; + my $b = $perm[1]; + my $c = $perm[2]; + my $d = $perm[3]; + my $e = $perm[4]; + my $f = $perm[5]; + my $g = $perm[6]; + + say <<"END"; + a = $a e = $e + b = $b f = $f + c = $c g = $g + d = $d + Box1 = a + b = $a + $b = $b1 + Box2 = b + c + d = $b + $c + $d = $b2 + Box3 = d + e + f = $d + $e + $f = $b3 + Box4 = f + g = $f + $g = $b4 +END + + } + +} + +sub _box_1( @array ) { + return $array[0] + $array[1]; +} + +sub _box_2( @array ) { + return $array[1] + $array[2] + $array[3]; +} + +sub _box_3( @array ) { + return $array[3] + $array[4] + $array[5]; +} + +sub _box_4( @array ) { + return $array[5] + $array[6]; +} |