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| -rw-r--r-- | challenge-137/dave-jacoby/blog.txt | 1 | ||||
| -rw-r--r-- | challenge-137/dave-jacoby/perl/ch-1.pl | 56 | ||||
| -rw-r--r-- | challenge-137/dave-jacoby/perl/ch-2.pl | 60 |
3 files changed, 117 insertions, 0 deletions
diff --git a/challenge-137/dave-jacoby/blog.txt b/challenge-137/dave-jacoby/blog.txt new file mode 100644 index 0000000000..ab97ea3038 --- /dev/null +++ b/challenge-137/dave-jacoby/blog.txt @@ -0,0 +1 @@ +https://jacoby.github.io/2021/11/01/2020-was-a-long-year-the-weekly-challenge-137.html diff --git a/challenge-137/dave-jacoby/perl/ch-1.pl b/challenge-137/dave-jacoby/perl/ch-1.pl new file mode 100644 index 0000000000..2a93667f0d --- /dev/null +++ b/challenge-137/dave-jacoby/perl/ch-1.pl @@ -0,0 +1,56 @@ +#!/usr/bin/env perl + +use strict; +use warnings; +use feature qw{ say state postderef signatures }; +no warnings qw{ experimental }; + +use DateTime; + +# This table shows how this will work for any given year +# +# dow => day of week (numerical) +# leap => is a leap year (bool) +# woy => week of year (1, 52, 53) +# +# dow leap woy day +# --------------------------------------- +# 1 0 1 Monday +# 1 1 1 Monday +# 2 0 1 Tuesday +# 2 1 1 Tuesday +# 3 0 1 Wednesday +# 3 1 1 Wednesday +# 4 0 53 Thursday +# 4 1 53 Thursday +# 5 0 52 Friday +# 5 1 53 Friday +# 6 0 52 Saturday +# 6 1 52 Saturday +# 7 0 52 Sunday +# 7 1 52 Sunday + +my @years; +for my $year ( 1900 .. 2100 ) { + my $dt = DateTime->new( + month => 12, + day => 31, + year => $year, + ); + my ( undef, $week_of_year ) = $dt->week; + my $dow = $dt->day_of_week; + my $nam = $dt->day_name; + my $is_leap = $dt->is_leap_year; + push @years, $year if $week_of_year == 53; +} + +my @x; +while (@years) { + push @x, shift @years; + if ( scalar @x == 5 ) { + say join ', ', @x, ''; + @x = (); + } +} + +say join ', ', @x; diff --git a/challenge-137/dave-jacoby/perl/ch-2.pl b/challenge-137/dave-jacoby/perl/ch-2.pl new file mode 100644 index 0000000000..a6ad0430c2 --- /dev/null +++ b/challenge-137/dave-jacoby/perl/ch-2.pl @@ -0,0 +1,60 @@ +#!/usr/bin/env perl + +use strict; +use warnings; +use feature qw{ say postderef signatures state }; +no warnings qw{ experimental }; + +use Math::BigInt; +use Getopt::Long; +use List::Util qw{uniq}; + +my @examples; +my @numbers; +my $lychrel = 0; +GetOptions( + 'number=i' => \@numbers, + 'lychrel' => \$lychrel, +); + +if ( scalar @numbers ) { + @examples = uniq sort { $a <=> $b } @numbers; +} +else { @examples = ( 10 .. 1000 ); } + +for my $e (@examples) { + my $l = is_lychrel($e); + next if !$l && $lychrel; + say <<"END"; + Input: \$n = $e + Output: $l +END +} + +exit; + +sub is_lychrel($e) { + my $n = $e; + my $c = 0; + while ( !is_palindrome($n) ) { + $n = lychrel($n); + $c++; + return 1 if $c >= 500; + } + return 0; +} + +sub lychrel( $n ) { + my $bign = Math::BigInt->new($n); + my $u = join '', reverse split //, $n; + my $bigu = Math::BigInt->new($u); + my $new = $bign->badd($bigu); + return $new; +} + +sub is_palindrome ($n) { + my $u = join '', reverse split //, $n; + $u =~ s/^0+//mix; + return $u eq $n ? 1 : 0; +} + |