1. There to be a solution? 5
2. There to be 2 solutions? 6
3. There to be two solutions where both Hood and Tuck hit a run of rings, missing none inbetween? 7

[12:41:02] bucko(tank) ~$ scp test.jpg repo_up:
test.jpg                                    100%  110KB 110.3KB
Uploaded test.jpg (112971 bytes)

bucko@tank$ ssh-keygen -f ~bucko/.ssh/abhor_upload

#!/bin/sh
if [ "$SSH_ORIGINAL_COMMAND" != "scp -t ." -a "$SSH_ORIGINAL_COMMAND" != "scp -d -t ." -a "$SSH_ORIGINAL_COMMAND" != "scp -r -t ." -a "$SSH_ORIGINAL_COMMAND" != "scp -r -d -t ." ]; then
    printf "Can't login, noob. Command was: $SSH_ORIGINAL_COMMAND\r\n" >&2
    exit
fi
cd /home/repo/incoming
printf '\000'
while read MODE SIZE NAME; do
    case "$MODE" in
        C*)
            printf '\000'
            MODE=C0644
            SIZE16=$(echo $SIZE 16384 / p|dc)
            SIZEREMAIN=$(echo $SIZE $SIZE16 16384 \* - p|dc)
            FILENAME=$(basename $(tempfile .))

            if dd of=$FILENAME count=$SIZE16 ibs=16K 2> /dev/null && dd of=$FILENAME oflag=append conv=notrunc count=$SIZEREMAIN ibs=1 2> /dev/null; then
                echo "Uploaded $NAME ($SIZE bytes)" >&2
                dd ibs=1 of=/dev/null count=1 2> /dev/null # null char
                # Magic to queue the image into the archiver
                printf '\000'
            else
                rm "$FILENAME"
                printf '\002Failure!\n'
            fi
        ;;
        *) # Ignore D, E and T messages, as we don't care!
            printf "\000"
        ;;
    esac
done

no-port-forwarding,no-X11-forwarding,no-agent-forwarding,no-pty,command="/home/repo/bin/ssh_incoming_upload" ssh-rsa KEYFINGERPRINTHERE bucko@tank

Host repo_up
HostName abhor.co.uk
User repo
IdentityFile ~/.ssh/abhor_upload

Inspired by a game which I saw mentioned in David Mond's Maths of Climate Change talk (actually, I read it rather than watched it), I've started a new competition. The aim is to save the planet!

Outline

There is a bot in #SaveThePlanet, on IRC server irc.uwcs.co.uk which listens for commands (rough protocol docs are available). It maintains a world state in which you have to, well, save the planet.

It's not always possible; you may be doomed. In fact, if you're playing against a number of evil entities intent on destroying the world, the world will be destroyed.

Climate badness is modeled by "chance of a disaster per tick", and is initially random. You can donate money per tick and hold industries. The more you donate, the better it is for the climate, and the more industry, the worse. The actual factors involved are picked at random per game, as is your initial industry count (more industry means more influence, but more likely to get disastered).

Should you save the world (read: restore climate to 0), the player who gained the most industry wins. Should you melt down the world, the player who donate the most wins. (See protocol document for specifics.)

Competition

The game will be running until the end of term. Each game will score points for the players who came out on top, and those points will be summed up over the day to produce a total. This orders the players for the day and gives points (6 for first place, 3 for second, 2 for third and 1 for fourth). Points are again aggregated over a week, and the weekly winners get prizes. Next week is a warmup (I'll use it to tweak the scoring and the game in general).

Each game, the bot picks between 2 and number of players asking to participate, and kills off the rest (players who've been in more games recently will be killed off more often) with no penalty, in order to give variation in the type of game you face.

The first competitive week runs from 00:00 Sat to 00:00 Sat over Week 9. The final week runs only until 00:00 Fri Week 10, to give me time to work out who won and present prizes at the CompSoc LAN. The final week will have £30 to the winner, £20 to runner up and £10 to third place. Prizes for the first week are undecided.

Sample code

Current version of the game bot is at: http://www.bucko.me.uk/competitions/SaveThePlanet/game.pl.txt

A sample bot (actually, 3), written in Perl, is at: http://www.bucko.me.uk/competitions/SaveThePlanet/sample.pl.txt (passwords are read from a separate file).

A Java sample using pIRCbot, is at: http://www.bucko.me.uk/competitions/SaveThePlanet/jarvur.

Win Data

You can get XML data about recent games:

• Last few games
• Last 10 games
• Today's games

Other stuff

I'll update this post as I tweak the algorithm until the start of the first week. The above code will be updated, too.

Prize is open to anyone I know and any member of CompSoc, plus anyone I feel like allowing to get the prize. If you wish to not be included in the prize giving, you can still compete, but let me know.

Good luck!

Delightful. I've been encoding some DVDs recently, and twice I've left it going on one job and returned to find my system was off, after logging the following:

May 21 06:14:35 tank kernel: [24200.843888] ACPI: Critical trip point
May 21 06:14:35 tank kernel: [24200.843888] ACPI: Unable to turn cooling device [ffff8101af06f8b0] 'on'
May 21 06:14:35 tank shutdown[27159]: shutting down for system halt
May 21 07:51:14 tank syslogd 1.5.0#5: restart.

The second time, the encode jobs appeared to have finished (I had a valid and complete AVI file), yet the system still cut out. They were simultaneous and of different lengths, so they would have finished at different times.

Further, I've been checking on sensors - the ACPI thermal_zone temperature at /proc/acpi/thermal_zone/THRM/temperature reports the same value as the w83627ehf device - specifically, 22C at idle, maybe 55C max at load. This seems pretty normal to me. The core temperatures are more worrying, at 45C idle, 82C load.

I've got a stock HSF on an E6600 at default clock. When at load, I've also got a noisy 120mm fan pointing directly at the HSF with the case open.

Are these numbers normal? If so, what's going on? Internet won't even tell me normal coretemp numbers...

Some people probably know I'm going through a password reset period right now. Included in this is my banking passwords for NatWest, Alliance and Leicester and Egg.

I have made some worrying observations to this end. Firstly, NatWest and Egg (at the least) ask for individual characters on login. This practice reduces the user's ability to add security by pre/app-ending a long known phrase to their password as an unguessable salt, but on the plus side makes it harder to keylog a password. More worrying, however, is the following bizarre password policies employed by the banks:

As you can see, there's some fairly arbitrary restrictions here. Why aren't I allowed to use symbols? Why does 2 digits and one letter make a password secure (considering, say, may12, meets this criteria)?

Do any banks let you use hardcore passwords? It'd be great if people could play around and let me know various banks' policies on passwords.

I frequently have to send messages to large numbers of people, namely the leaders of clans on the KGS Clans System. This is tedious work as the client has an awful non-keyboard navigable UI. In fact, the minimal path to send a message turns out to be:

1. Start CGoban
2. Send space to press the default activated logiin button (return doesn't work).
3. Press return twice to log in with saved user/pass.
4. Wait for the rooms box to pop up.
5. Click the menu bar (can't use a keyboard shortcut...).
6. Navigate to the User menu. Press up to get to "leave message".
7. Press tab, as it defaults to having no widget in focus.
8. Type the target user.
9. Press tab or return.
10. Type the message.
11. As you are now unable to keyboard-navigate from the input box, click "OK".

I dread to think how the author would respond were some poor disabled person to explain how painful it is to operate that monster.

Today I coded a hack/fix for this problem. I have a shell script which automates this process using xvfb, xwininfo and xte. It is now fully integrated into my admin system so that I can message various groups of clan leaders.

Java is slow, meaning there are frequent "sleep" calls to ensure things happen. Also, xte does not seem to enjoy the company of xvfb. Specifically, "key colon" produces a semicolon unless surrounded by "keydown Shift_L" and "keyup Shift_L". This happens with capital letters and many other symbols. Additionally, "key :" works on my X server but apparently not on xvfb, and "str :" works locally but gives an X error on the remote. I am unsure as to how to fix the xte problem, and have left a kludge in the script to use Perl to manipulate a string into something it'll like. It only accepts a small number of symbols.

A humongous 2 entries to this one. There was a clear winner:

Zed0

Perl, filename must be '278951438'.

sub p{print 1+int$_/3,-1-$_%3;die}@_=map{(/O/?99:/X/?1:-1)*chop$0}split/\n?/,<>.<>.<>;map{$a=@_[$_];map{$b=@_[$_];$a*$b<0|$a+$b-@_[$_]-15||p for@z}0..$_-1}@z=0..8;@_[$_]<0&&p for@z

I can't pretend to understand what it does, but it does pass all of my tests. Total length is 181. I'm informed that the filename is a magic square which is solved to find possible lines.

Rupert Swarbrick

Once again attempting to golf in a non-golfable language. This one (factor) has compulsory whitespace, compulsory non-evaluation brackets, but at least no nasty angle brackets for me to quote in my HTML.

USING: arrays kernel math combinators io sequences namespaces assocs prettyprint ; IN: A SYMBOL: z : s swap ; : a 32 s index ; : b [ 1 + ] bi@ z get { { 1 [ s ] } { 2 [ dup rot 1 = [ ] [ 4 s - s ] if ] } [ drop ] } case "," s pprint write . ; input-stream get lines dup dup [ flip ] [ dup reverse [ [ s ?nth ] map-index ] bi@ 2array ] bi 3array >alist [ first2 s z set [ [ [ 88 = ] count 2 = ] [ a ] bi and ] find a dup [ b t ] [ drop ] if ] find [ 2drop ] [ drop 0 z set [ a ] find [ a b ] [ 2drop ] if* ] if

Total length: 517 bytes. It's over half a kibibyte! Rupert has outdone himself on this one.

More amusingly, his co-ordinates are backwards, meaning it fails half of the tests if I don't reverse them. :)

I think Rupert's aiming for the "points for participation" award, perhaps...

Problem

For those enjoying the challenge of the previous post, but wanting a little more, I'm setting the challenge of writing an AI for n by n by n naughts and crosses (n less than or equal to 30, say). You are aiming to get n in a row (that is, a line of maximal length on the grid).

Your code should accept input of Y-Z grids from X=1 to n, with "," separating lines, ";" separating grids, "X" representing an X, "O" representing an O and " " (space) representing a blank space. You are to infer the size from this input.

For example:

    ,  X ,    ,    ;    ,    ,    ,    ;    , O  ,    ,    ;    ,    ,    ,    

This grid has an X on (1, 2, 3) and an O on (3, 2, 2).

You are to assume that you are playing naughts. Your code should output 3 numbers in bracket notation, with a newline, representing the (x, y, z) co-ordinates it wishes to play, for example "(1, 4, 2)\n" to play at x=1, y=4, z=2. It may take as long as it likes to do this (within reason; code which takes a very long time per move may be killed), but see below.

Your code may then exit (in which case it will be rerun with the grid which contains its own move and the response), or it may await a response move in the same "(X, Y, Z)\n" format before moving again.

The first item on the command line will always be the name of its opponent. For the same opponent, this is guaranteed to be the same, so that a learning AI may choose to scrap its cache between opponents.

Submission

Your submission should be either a source file or an archive of files. Provide some adequate instructions on how to execute it - and ensure these are easy to follow on either a 32-bit or 64-bit Debian system (64-bit preferred). Your entry will be run in its own directory, with which it is free to do as it pleases (but do not create files larger than around 100MB in total - if you are creating many large files, please note in your submission which of these may be deleted and when).

Your entry will be scored on code quality, speed and skill. All three are worth the same. Code quality will be judged by hand. Speed will be determined by the time taken to run a number of vs. matches against other AI, as will skill. These matches will probably take place on 4x4x4 or 5x5x5 boards, but your entry will be tested to ensure it at least understands how to win and block wins on larger boards. It should therefore ensure it does not spend a long time thinking about these.

Mail submissions to isreal-progcomp20090125@bucko.me.uk by the end (BST) of 25th Jan 2009.

Prizes

Prizes for winners are quite possible if the submissions are of a reasonable quality. These may be in the form of T-shirts, book tokens or similar.

Sample Code

I have written some sample code and put it online at http://www.bucko.me.uk/progcomp20090125.tar.bz2. There are two samples: uk.me.bucko.progcomp20090125.FirstEmpty and uk.me.bucko.progcomp20090125.Random. Compile them with javac uk/me/bucko/progcomp20090125/*.java; run a test with java uk.me.bucko.progcomp20090125.Test uk.me.bucko.progcomp20090125.Random uk.me.bucko.progcomp20090125.FirstEmpty 5 (for 5x5x5). Don't complain about my poor code! It's up to you to make it better if it sucks - but it does work.

Problem

Your task, should you choose to accept it, is to write an "AI" for the Naughts and Crosses. The only requirement is that your AI must, if it is possible, prevent its opponent from winning on their next move: it must block a three in a row if one is threatened. If many are threatened it must block at least one. It may not win unless this also directly blocks a win by its opponent (or there are no blocks that can be made). Otherwise it may play anywhere legal.

Input will be three lines containing X, O or space characters. You must output, on STDOUT, two integers with some amount of non-numeric separating them containing the co-ordinates to place an 'O' (the output must match the Perl regex m/(\d+)\D+(\d+)/s). The top left is (1,1); the first digit is the X co-ordinate, so the top right is (1,3). For example:

echo "X O"; echo "XOO"; echo "   "

A trivial solution to this example is the script: perl -e 'print"3,1"'

Submissions

You must submit either a command line or a source file. If you submit a command line, the full character length of the line will be used as your score. If you submit a source file, it should be executable via your chosen language's interpreter or compilable via the compiler, and the byte length of the file will be your score. If you require command line options to run, interpret or compile your code, they will be added to your source length (this includes any whitespace, so "perl -n filename" costs 3 extra characters). If your code is to be compiled, you may choose the compiled length over the source length if it is shorter.

You may use any language that I can either apt-get install onto my 32-bit or 64-bit Debian chroots, or that you provide simple instructions for me to get running on said chroot. If I can't even get the language to run, you score 9001.

Submissions to isreal-progcomp20090104@bucko.me.uk by the end of 4th January (BST).

The lowest score wins. Lowest alphanumerics breaks the tie, and further silly tiebreakers will break any further ties.

Extra

If enough people also submit an AI that can win if it is possible (this includes punishing mistakes, so "O \n X \n O" requires a move in a corner), this will also be judged in a separate category.