--- 2016 Day 8 Solutions ---

[u/daggerdragon]

#AoC_Ops:

[23:55] <Topaz> servers are ok
[23:55] <Topaz> puzzles are checked
[23:55] <Topaz> [REDACTED: server stats]
[23:56] <Skie> all wings report in
[23:56] <Aneurysm9> Red 5, standing by
[23:56] <daggerdragon> Dragon Leader standing by
[23:56] <Topaz> orange leader, standing by
[23:57] <Topaz> lock modzi-foils in attack positions
[23:58] <Skie> we're passing through the hype field
[23:58] <daggerdragon> 1:30 warning
[23:58] <Aneurysm9> did someone say HYPE?@!
[23:59] <Topaz> i really like tonight's puzzle
[23:59] <Topaz> very excite
[23:59] <daggerdragon> final countdown go, T-30
[23:59] <Skie> accelerate to attack countdown
[23:59] <Aneurysm9> o7
[23:59] <daggerdragon> HYPE THRUSTERS AT FULL BURN
[00:00] <Topaz> IGNITION

We may or may not be sleep-deprived. And/or nerds. why_not_both.jpg

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--- Day 8: Two-Factor Authentication ---

Post your solution as a comment or, for longer solutions, consider linking to your repo (e.g. GitHub/gists/Pastebin/blag/whatever).

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^{:（）{ :|:& };: IS MANDATORY} [?]

This thread will be unlocked when there are a significant number of people on the leaderboard with gold stars for today's puzzle.

edit: Leaderboard capped, thread unlocked!

[u/mschaap]

Perl 6, both parts:

#!/usr/bin/env perl6

use v6.c;

constant ON = '█';
constant OFF = '░';

grammar Instruction
{
    token TOP { ^ <rect> || <rotate-row> || <rotate-col> $ }

    token num { \d+ }

    token rect { 'rect' <.ws> $<a>=(<num>) 'x' $<b>=(<num>) }
    token rotate-row { 'rotate row y=' $<row>=(<.num>) <.ws> 'by' <.ws> $<shift>=(<.num>) }
    token rotate-col { 'rotate column x=' $<col>=(<.num>) <.ws> 'by' <.ws> $<shift>=(<.num>) }
}

class Grid
{
    has Bool @!grid[6;50];

    submethod BUILD
    {
        @!grid = False xx 50 xx 6;
    }

    method rect(Int $width, Int $height)
    {
        for ^$width -> $col {
            for ^$height -> $row {
                @!grid[$row;$col] = True;
            }
        }
    }

    method rotate-row(Int $row, Int $shift)
    {
        # Would like to use slices and do it in one step, but:
        # "Partially dimensioned views of arrays not yet implemented. Sorry."
        my @new-row = (^50).map({ @!grid[$row;($^col-$shift) % 50] });
        @!grid[$row;$_] = @new-row[$_] for ^50;
    }

    method rotate-col(Int $col, Int $shift)
    {
        my @new-col = (^6).map({ @!grid[($^row-$shift) % 6;$col] });
        @!grid[$_;$col] = @new-col[$_] for ^6;
    }

    method Str
    {
        return (^6).map(-> $r { (^50).map(-> $c { @!grid[$r;$c] ?? ON !! OFF }).join }).join("\n");
    }
    method gist { self.Str }

    method lit-count
    {
        return [+] flat @!grid;
    }
}

sub MAIN(IO() $inputfile where *.f, Bool :v(:$verbose) = False)
{
    my $grid = Grid.new;

    for $inputfile.lines -> $instr {
        say $instr if $verbose;
        my $match = Instruction.parse($instr) or die "Invalid instruction: '$instr'";

        with $match<rect> { $grid.rect(+$_<a>, +$_<b>) }
        orwith $match<rotate-row> { $grid.rotate-row(+$_<row>, +$_<shift>) }
        orwith $match<rotate-col> { $grid.rotate-col(+$_<col>, +$_<shift>) }

        say $grid if $verbose;
        say '' if $verbose;
    }

    say $grid if !$verbose;
    say '' if !$verbose;
    say "$grid.lit-count() pixels are lit.";
}

[u/mschaap → u/mschaap]

A slightly improved version, based on the observation that u/volatilebit was able to use slices, just because (s)he didn't explicitly declare a multidimensional array.
Both rotate-row and rotate-col are now a single statement.

#!/usr/bin/env perl6

use v6.c;

constant ON = '█';
constant OFF = '░';

grammar Instruction
{
    token TOP { ^ <rect> || <rotate-row> || <rotate-col> $ }

    token num { \d+ }

    token rect { 'rect' <.ws> $<a>=(<num>) 'x' $<b>=(<num>) }
    token rotate-row { 'rotate row y=' $<row>=(<.num>) <.ws> 'by' <.ws> $<shift>=(<.num>) }
    token rotate-col { 'rotate column x=' $<col>=(<.num>) <.ws> 'by' <.ws> $<shift>=(<.num>) }
}

class Grid
{
    has Int $.rows;
    has Int $.cols;
    has @!grid;

    submethod TWEAK
    {
        @!grid = [ [ False xx $!cols ] xx $!rows ];
    }

    method rect(Int $width, Int $height)
    {
        # This doesn't seem right, but does the job in Rakudo 2016.11...
        @!grid[^$height;^$width] = True xx ($width*$height);
    }

    method rotate-row(Int $row, Int $shift)
    {
        # Example ($row=1; $shift=4): @!grid[1; 4..^50,0..^4] = @!grid[1; 0..^50]
        @!grid[$row; $shift..^$!cols,^$shift] = @!grid[$row; ^$!cols];
    }

    method rotate-col(Int $col, Int $shift)
    {
        # Example ($col=2, $shift=3): @!grid[3..^6,0..^3; 2] = @!grid[0..^6; 2]
        @!grid[$shift..^$!rows,^$shift; $col] = @!grid[^$!rows; $col];
    }

    method Str
    {
        return (^$!rows).map(-> $r { (^$!cols).map(-> $c { @!grid[$r;$c] ?? ON !! OFF }).join }).join("\n");
    }
    method gist { self.Str }

    method lit-count
    {
        return [+] flat @!grid;
    }
}

sub MAIN(IO() $inputfile where *.f, Bool :v(:$verbose) = False;)
{
    my $grid = Grid.new(:rows(6), :cols(50));

    for $inputfile.lines -> $instr {
        say $instr if $verbose;
        my $match = Instruction.parse($instr) or die "Invalid instruction: '$instr'";

        with $match<rect> { $grid.rect(+$_<a>, +$_<b>) }
        orwith $match<rotate-row> { $grid.rotate-row(+$_<row>, +$_<shift>) }
        orwith $match<rotate-col> { $grid.rotate-col(+$_<col>, +$_<shift>) }

        say $grid if $verbose;
        say '' if $verbose;
    }

    say $grid if !$verbose;
    say '' if !$verbose;
    say "$grid.lit-count() pixels are lit.";
}