Year 2016, days 1-10: so far pretty interesting

diff --git a/2016/01.pl b/2016/01.pl
new file mode 100755 (executable)
index 0000000..42982f0
--- /dev/null
+++ b/2016/01.pl
@@ -0,0 +1,23 @@
+#!/usr/bin/perl -w
+
+use strict;
+use v5.30;
+
+my @dir = ([0, -1], [1, 0], [0, 1], [-1, 0]);
+my $d = 0;
+
+my ($x, $y) = (0, 0);
+
+$_ = <>;
+while (/([LR])(\d+)/g) {
+       if ($1 eq 'L') {
+               $d = $#dir if --$d < 0;
+       } else {
+               $d = 0 if ++$d > $#dir;
+       }
+       $x += $2 * $dir[$d]->[0];
+       $y += $2 * $dir[$d]->[1];
+}
+
+say abs($x)+abs($y);
+       

diff --git a/2016/02.pl b/2016/02.pl
new file mode 100755 (executable)
index 0000000..a860be8
--- /dev/null
+++ b/2016/02.pl
@@ -0,0 +1,30 @@
+#!/usr/bin/perl -w
+
+use strict;
+use v5.30;
+
+my @dir = ([0, -1], [1, 0], [0, 1], [-1, 0]);
+my $d = 0;
+
+my ($x, $y) = (0, 0);
+
+$_ = <>;
+my %seen;
+while (/([LR])(\d+)/g) {
+       if ($1 eq 'L') {
+               $d = $#dir if --$d < 0;
+       } else {
+               $d = 0 if ++$d > $#dir;
+       }
+       my $i = $2;
+       while ($i--) {
+               $x += $dir[$d]->[0];
+               $y += $dir[$d]->[1];
+               if ($seen{$x,$y}++) {
+                       say abs($x)+abs($y);
+                       exit 0;
+               }
+       }
+}
+
+       

diff --git a/2016/03.pl b/2016/03.pl
new file mode 100755 (executable)
index 0000000..ca698da
--- /dev/null
+++ b/2016/03.pl
@@ -0,0 +1,32 @@
+#!/usr/bin/perl -w
+
+use strict;
+use v5.30;
+
+$; = ',';
+my %pos2num = (
+       "0,0" => 1,
+       "1,0" => 2,
+       "2,0" => 3,
+       "0,1" => 4,
+       "1,1" => 5,
+       "2,1" => 6,
+       "0,2" => 7,
+       "1,2" => 8,
+       "2,2" => 9,
+);
+my @pos = (1, 1);
+my $ret = '';
+while (<>) {
+       chomp;
+       for my $step (split //) {
+               $pos[0]-- if $pos[0] && $step eq 'L';
+               $pos[0]++ if $pos[0] < 2 && $step eq 'R';
+               $pos[1]-- if $pos[1] && $step eq 'U';
+               $pos[1]++ if $pos[1] < 2 && $step eq 'D';
+       }
+       $ret .= $pos2num{$pos[0],$pos[1]};
+}
+
+say $ret;
+

diff --git a/2016/04.pl b/2016/04.pl
new file mode 100755 (executable)
index 0000000..aa06da1
--- /dev/null
+++ b/2016/04.pl
@@ -0,0 +1,36 @@
+#!/usr/bin/perl -w
+
+use strict;
+use v5.30;
+
+$; = ',';
+my %pos2num = (
+       "2,0" => 1,
+       "1,1" => 2,
+       "2,1" => 3,
+       "3,1" => 4,
+       "0,2" => 5,
+       "1,2" => 6,
+       "2,2" => 7,
+       "3,2" => 8,
+       "4,2" => 9,
+       "1,3" => 'A',
+       "2,3" => 'B',
+       "3,3" => 'C',
+       "2,4" => 'D',
+);
+my @pos = (0, 2);
+my $ret = '';
+while (<>) {
+       chomp;
+       for my $step (split //) {
+               $pos[0]-- if $pos2num{ ($pos[0]-1).",$pos[1]" } && $step eq 'L';
+               $pos[0]++ if $pos2num{ ($pos[0]+1).",$pos[1]" } && $step eq 'R';
+               $pos[1]-- if $pos2num{ "$pos[0],".($pos[1]-1) } && $step eq 'U';
+               $pos[1]++ if $pos2num{ "$pos[0],".($pos[1]+1) } && $step eq 'D';
+       }
+       $ret .= $pos2num{$pos[0],$pos[1]};
+}
+
+say $ret;
+

diff --git a/2016/05.pl b/2016/05.pl
new file mode 100755 (executable)
index 0000000..9d52104
--- /dev/null
+++ b/2016/05.pl
@@ -0,0 +1,13 @@
+#!/usr/bin/perl -w
+
+use strict;
+use v5.30;
+
+my $valid;
+while (<>) {
+       chomp;
+       my (@d) = sort { $a <=> $b } /(\d+)/g;
+       $valid++ if $d[0]+$d[1] > $d[2];
+}
+
+say $valid;

diff --git a/2016/06.pl b/2016/06.pl
new file mode 100755 (executable)
index 0000000..d11ed98
--- /dev/null
+++ b/2016/06.pl
@@ -0,0 +1,20 @@
+#!/usr/bin/perl -w
+
+use strict;
+use v5.30;
+
+my $valid;
+my @d;
+while (<>) {
+       chomp;
+       push @d, [ /(\d+)/g ];
+       if (@d == 3) {
+               for my $c (0 .. 2) {
+                       my @t = sort { $a <=> $b } ($d[0][$c], $d[1][$c], $d[2][$c]);
+                       $valid++ if $t[0]+$t[1] > $t[2];
+               }
+               @d = ();
+       }
+}
+
+say $valid;

diff --git a/2016/07.pl b/2016/07.pl
new file mode 100755 (executable)
index 0000000..fd8ba32
--- /dev/null
+++ b/2016/07.pl
@@ -0,0 +1,19 @@
+#!/usr/bin/perl -w
+
+use strict;
+use v5.30;
+
+my $sum;
+while (<>) {
+       chomp;
+       my ($code, $id, $csum) = /\A([a-z-]+)-(\d+)\[([a-z]{5})\]/;
+       my %hist;
+       $hist{$&}++ while ($code =~ /[a-z]/g);
+       my $c1;
+       for my $l (sort { $hist{$b} <=> $hist{$a} || $a cmp $b } keys %hist) {
+               $c1 .= $l;
+               last if length $c1 >= length $csum;
+       }
+       $sum += $id if $csum eq $c1;
+}
+say $sum;

diff --git a/2016/08.pl b/2016/08.pl
new file mode 100755 (executable)
index 0000000..80fa433
--- /dev/null
+++ b/2016/08.pl
@@ -0,0 +1,20 @@
+#!/usr/bin/perl -w
+
+use strict;
+use v5.30;
+
+my $sum;
+while (<>) {
+       chomp;
+       my ($code, $id, $csum) = /\A([a-z-]+)-(\d+)\[([a-z]{5})\]/;
+       my $d;
+       $code =~ s/-/ /g;
+       for (split //, $code) {
+               if ($_ eq ' ') {
+                       $d .= ' ';
+                       next;
+               }
+               $d .= chr(ord('a') + ((ord($_)-ord('a')+$id) % 26));
+       }
+       say $id if $d =~ /pole/;
+}

diff --git a/2016/09.pl b/2016/09.pl
new file mode 100755 (executable)
index 0000000..6952777
--- /dev/null
+++ b/2016/09.pl
@@ -0,0 +1,20 @@
+#!/usr/bin/perl -w
+
+use strict;
+use v5.30;
+
+use Digest::MD5 qw(md5_hex);
+
+my $id = 'ugkcyxxp';
+my $pass = '';
+my $i = 0;
+while (length($pass) < 8) {
+       my $h = md5_hex($id.$i);
+       if ($h =~ /\A00000/) {
+               $pass .= substr($h, 5, 1);
+       }
+       $i++;
+}
+
+say $pass;
+               

diff --git a/2016/10.pl b/2016/10.pl
new file mode 100755 (executable)
index 0000000..54a7009
--- /dev/null
+++ b/2016/10.pl
@@ -0,0 +1,23 @@
+#!/usr/bin/perl -w
+
+use strict;
+use v5.30;
+
+use Digest::MD5 qw(md5_hex);
+
+my $id = 'ugkcyxxp';
+my $pass = ' ' x 8;
+my $i = 0;
+while ($pass =~ /\s/) {
+       my $h = md5_hex($id.$i);
+       if ($h =~ /\A00000/) {
+               my $pos = substr($h, 5, 1);
+               if ($pos =~ /[0-7]/ && substr($pass, $pos, 1) eq ' ') {
+                       substr($pass, $pos, 1) = substr($h, 6, 1);
+               }
+       }
+       $i++;
+}
+
+say $pass;
+               

diff --git a/2016/11.pl b/2016/11.pl
new file mode 100755 (executable)
index 0000000..bb43630
--- /dev/null
+++ b/2016/11.pl
@@ -0,0 +1,24 @@
+#!/usr/bin/perl -w
+
+use strict;
+use v5.30;
+
+my %h;
+while (<>) {
+       chomp;
+       my $i = 0;
+       for my $l (split //) {
+               $h{$i++}{$l}++;
+       }
+}
+
+my $p;
+
+for my $i (0..7) {
+       my @a = sort { $h{$i}{$b} <=> $h{$i}{$a} } keys %{ $h{$i} };
+       $p .= $a[0];
+}
+
+say $p;
+               
+               

diff --git a/2016/12.pl b/2016/12.pl
new file mode 100755 (executable)
index 0000000..7d7d68d
--- /dev/null
+++ b/2016/12.pl
@@ -0,0 +1,24 @@
+#!/usr/bin/perl -w
+
+use strict;
+use v5.30;
+
+my %h;
+while (<>) {
+       chomp;
+       my $i = 0;
+       for my $l (split //) {
+               $h{$i++}{$l}++;
+       }
+}
+
+my $p;
+
+for my $i (0..7) {
+       my @a = sort { $h{$i}{$b} <=> $h{$i}{$a} } keys %{ $h{$i} };
+       $p .= $a[-1];
+}
+
+say $p;
+               
+               

diff --git a/2016/13.pl b/2016/13.pl
new file mode 100755 (executable)
index 0000000..8809677
--- /dev/null
+++ b/2016/13.pl
@@ -0,0 +1,16 @@
+#!/usr/bin/perl -w
+
+use strict;
+use v5.30;
+
+my $count;
+
+while (<>) {
+       chomp;
+       next if /\[[^\]]*(\w)(?!\1)(\w)\2\1/;
+       next if !/(\w)(?!\1)(\w)\2\1/;
+       $count++;
+       say;
+}
+
+say $count;

diff --git a/2016/14.pl b/2016/14.pl
new file mode 100755 (executable)
index 0000000..4694715
--- /dev/null
+++ b/2016/14.pl
@@ -0,0 +1,24 @@
+#!/usr/bin/perl -w
+
+use strict;
+use v5.30;
+
+my $count;
+
+line:
+while (<>) {
+       chomp;
+       my $super = $_;
+       $super =~ s/\[.*?\]/---/g;
+       my $hyper = join('---', ($_ =~ /\[([^\]]*)\]/g));
+       while ($super =~ /(\w)(?!\1)(\w)\1/g) {
+               pos($super)-= 2;
+               my $s = "$2$1$2";
+               if ($hyper =~ /$s/) {
+                       $count++;
+                       next line;
+               }
+       }
+}
+
+say $count;

diff --git a/2016/15.pl b/2016/15.pl
new file mode 100755 (executable)
index 0000000..c8fbd7c
--- /dev/null
+++ b/2016/15.pl
@@ -0,0 +1,38 @@
+#!/usr/bin/perl -w
+
+use strict;
+use v5.30;
+
+my %screen;
+my ($w, $h) = (50, 6);
+$; = ',';
+
+while (<>) {
+       if (/rect (\d+)x(\d+)/) {
+               for my $x (0 .. $1-1) {
+               for my $y (0 .. $2-1) {
+                       $screen{$x,$y} = 1;
+               } }
+       } elsif (/rotate row y=(\d+) by (\d+)/) {
+               my %ns = %screen;
+               for my $x (0 .. $w-1) {
+                       my $sx = $x - $2;
+                       $sx += $w if $sx < 0;
+                       $ns{$x,$1} = $screen{$sx,$1};
+               }
+               %screen = %ns;
+       } elsif (/rotate column x=(\d+) by (\d+)/) {
+               my %ns = %screen;
+               for my $y (0 .. $h-1) {
+                       my $sy = $y - $2;
+                       $sy += $h if $sy < 0;
+                       $ns{$1,$y} = $screen{$1,$sy};
+               }
+               %screen = %ns;
+       }
+}
+
+my $sum =()= grep { $screen{$_} } keys %screen;
+
+say $sum;
+

diff --git a/2016/16.pl b/2016/16.pl
new file mode 100755 (executable)
index 0000000..4e68ebe
--- /dev/null
+++ b/2016/16.pl
@@ -0,0 +1,41 @@
+#!/usr/bin/perl -w
+
+use strict;
+use v5.30;
+
+my %screen;
+my ($w, $h) = (50, 6);
+$; = ',';
+
+while (<>) {
+       if (/rect (\d+)x(\d+)/) {
+               for my $x (0 .. $1-1) {
+               for my $y (0 .. $2-1) {
+                       $screen{$x,$y} = 1;
+               } }
+       } elsif (/rotate row y=(\d+) by (\d+)/) {
+               my %ns = %screen;
+               for my $x (0 .. $w-1) {
+                       my $sx = $x - $2;
+                       $sx += $w if $sx < 0;
+                       $ns{$x,$1} = $screen{$sx,$1};
+               }
+               %screen = %ns;
+       } elsif (/rotate column x=(\d+) by (\d+)/) {
+               my %ns = %screen;
+               for my $y (0 .. $h-1) {
+                       my $sy = $y - $2;
+                       $sy += $h if $sy < 0;
+                       $ns{$1,$y} = $screen{$1,$sy};
+               }
+               %screen = %ns;
+       }
+}
+
+for my $y (0 .. $h-1) {
+       for my $x (0 .. $w-1) {
+               print $screen{$x,$y} ? '#' : ' ';
+       }
+       print "\n";
+}
+

diff --git a/2016/17.pl b/2016/17.pl
new file mode 100755 (executable)
index 0000000..768cda1
--- /dev/null
+++ b/2016/17.pl
@@ -0,0 +1,17 @@
+#!/usr/bin/perl -w
+
+use strict;
+use v5.30;
+
+chomp (my $in = <>);
+while ($in =~ /\((\d+)x(\d+)\)/g) {
+       my $p = pos($in) - length("($1x$2)");
+       my $str = substr($in, pos($in), $1);
+       my $repl = $str x $2;
+       say "repl=$repl";
+       substr($in, $p, length($str)+length("($1x$2)")) = $repl;
+       pos($in) = $p + length $repl;
+}
+
+say $in;
+say length $in;

diff --git a/2016/18.pl b/2016/18.pl
new file mode 100755 (executable)
index 0000000..c1eef09
--- /dev/null
+++ b/2016/18.pl
@@ -0,0 +1,21 @@
+#!/usr/bin/perl -w
+
+use strict;
+use v5.30;
+
+sub str_len {
+       my ($in) = @_;
+       my $l = 0;
+       while ($in) {
+               $l++ while $in =~ s/\A[A-Z]//;
+               next if $in !~ /\A\((\d+)x(\d+)\)/;
+               my $str = substr($in, length("($1x$2)"), $1);
+               substr($in, 0, length("($1x$2)") + $1) = '';
+               my $c = $2;
+               $l += $c * str_len($str);
+       }
+       return $l;
+}
+
+chomp (my $in = <>);
+say str_len($in);

diff --git a/2016/19.pl b/2016/19.pl
new file mode 100755 (executable)
index 0000000..efe1e0d
--- /dev/null
+++ b/2016/19.pl
@@ -0,0 +1,44 @@
+#!/usr/bin/perl -w
+
+use strict;
+use v5.30;
+
+my @bot_has;
+my @todo;
+my @outp;
+my @rule;
+while (<>) {
+       chomp;
+       if (/value (\d+) goes to bot (\d+)/) {
+               push @{ $bot_has[$2] }, $1;
+               push @todo, $2 if @{ $bot_has[$2] } == 2;
+       } elsif (/bot (\d+) gives low to (\w+) (\d+) and high to (\w+) (\d+)/) {
+               $rule[$1] = [ $2, $3, $4, $5 ];
+       } else {
+               die $_;
+       }
+}
+
+while (my $bot = shift @todo) {
+       my ($lo, $hi) = sort { $a <=> $b } @{ $bot_has[$bot] };
+       if ($lo == 17 && $hi == 61) {
+               say "$bot";
+               last;
+       }
+       my @r = @{ $rule[$bot] };
+       if ($r[0] eq 'output') {
+               $outp[$r[1]] = $lo;
+       } else {
+               push @{ $bot_has[$r[1]] }, $lo;
+               push @todo, $r[1] if @{ $bot_has[$r[1]] } == 2;
+       }
+       
+       if ($r[2] eq 'output') {
+               $outp[$r[3]] = $hi;
+       } else {
+               push @{ $bot_has[$r[3]] }, $hi;
+               push @todo, $r[3] if @{ $bot_has[$r[3]] } == 2;
+       }
+}
+       
+

diff --git a/2016/20.pl b/2016/20.pl
new file mode 100755 (executable)
index 0000000..15483c7
--- /dev/null
+++ b/2016/20.pl
@@ -0,0 +1,47 @@
+#!/usr/bin/perl -w
+
+use strict;
+use v5.30;
+
+my @bot_has;
+my @todo;
+my @outp;
+my @rule;
+while (<>) {
+       chomp;
+       if (/value (\d+) goes to bot (\d+)/) {
+               push @{ $bot_has[$2] }, $1;
+               push @todo, $2 if @{ $bot_has[$2] } == 2;
+       } elsif (/bot (\d+) gives low to (\w+) (\d+) and high to (\w+) (\d+)/) {
+               $rule[$1] = [ $2, $3, $4, $5 ];
+       } else {
+               die $_;
+       }
+}
+
+while (defined(my $bot = shift @todo)) {
+       my ($lo, $hi) = sort { $a <=> $b } @{ $bot_has[$bot] };
+       say "evaluating bot $bot which has $lo and $hi";
+       if ($lo == 17 && $hi == 61) {
+               say "$bot";
+       }
+       my @r = @{ $rule[$bot] };
+       if ($r[0] eq 'output') {
+               $outp[$r[1]] = $lo;
+               say "output $r[1] => $lo";
+       } else {
+               push @{ $bot_has[$r[1]] }, $lo;
+               push @todo, $r[1] if @{ $bot_has[$r[1]] } == 2;
+       }
+       
+       if ($r[2] eq 'output') {
+               $outp[$r[3]] = $hi;
+               say "output $r[3] => $hi";
+       } else {
+               push @{ $bot_has[$r[3]] }, $hi;
+               push @todo, $r[3] if @{ $bot_has[$r[3]] } == 2;
+       }
+}
+       
+say $outp[0] * $outp[1] * $outp[2];
+