Bitcoin Bolt

This post was released for Issue 16 of Bitcoin Magazine as part of a series of  articles about puzzles and games that started with Issue 12.

Packing problems are a class of optimization problems in mathematics that involve attempting to pack objects together into containers. The goal is to either pack a single container as densely as possible or pack all objects using as few containers as possible.

One of my earliest games (Hippos & Crocodiles – 2009) exploits this type of problem. In Hippos & Crocodiles your goal is to place as many animals on an African river as you can and prevent your opponent from doing the same.

Here I present a nice derivative of this game, while introducing a type of puzzle piece that has been around for more than a century: the polyomino, and also the concept of harvesting (picking items already placed on the board).

A polyomino is a plane geometric figure formed by joining one or more equal squares edge to edge. We can create 12 polyominos by joining 5 squares. These shapes are called pentominoes.

Figure 1: the 12 different pentominoes

There are other sizes of polyominoes (4,6,7…), but the pentomino is the one that works better for this game.

THE GAME: BITCOIN HARVEST

Bitcoin Harvest is a paper-and-pencil game for 2 or more players. Some solitary puzzles can be found at the end of this article, too.

Start by drawing a rectangular grid of any size. 10×10 is recommended for beginners, but for more than 2 players you might need a bigger grid.

Figure 2: the game grid

Secondly, and by turn, each player chooses a pentomino shape. This pentomino will be his ‘harvester’, and the only piece he will use during the game.

Example: Ann chooses the ‘L’, Ben chooses the ‘+’, Claire chooses the ‘U’.

Figure 3: the players’ harvesters (we’re using different colours for clarity)

The player that chose a shape in first place draws two coins in any empty cells of the grid.

Figure 4: the first player draws two coins

Then, starting with the second player, players take turns doing the following:

1. Draw your harvester on the board, so it doesn’t overlap other previously drawn pentominos and no parts of it land outside the board. You can (and should) draw it so it overlaps some coins. Notice that you can draw it rotated or mirrored, as long as it fits with the grid.

2. Score as many coins as the pentomino has covered.

3. Draw another 2 coins in any two empty spaces (not occupied by coins or pentominoes).

4. Pass your turn to the next player.

If you’re not capable of legally drawing a pentomino (no room for it) you must pass your turn. If all players pass in succession the game ends. The player with the highest score wins.

Here are a few examples of turns:

Figure 5: Ben draws his harvester collecting 1 coin, then draws two more coins.

Figure 6: Claire draws her harvester collecting 1 coin, then draws two more coins

Figure 7: Ann cleverly draws her harvester (scoring another coin) and then draws 2 coins next to it, ensuring their capture on her next turn!

 CHALLENGES

Here are a few puzzles for a single player. Use a single pentomino.

Challenge 1 (easy): Which pentomino is not capable of harvesting all these coins?

Figure 8: At least one pentomino is not capable of harvesting all these coins

Challenge 2 (medium): Which pentomino can harvest all the coins in figure 8 in the minimum number of turns? There can be several pentominoes that achieve the same result.

Challenge 3 (medium): Distribute 10 coins in a 8×8 grid so that the ‘L’ pentomino needs the maximum number of turns to harvest all of them (but no coin is left uncollected).

Please post your answers in my forum:

http://nestorgames.freeforums.org/bitcoin-magazine-puzzles-f16.html

… and I will reward the best post with a copy of one of my games. I’m looking forward to discussing your findings. Thank you for reading!

You might also enjoy my previous posts:

– Bitcoinstellations

– Rise of the machines

– Creativity as problem solving

– The Bitcoin Maze

The post The Bitcoin Harvest appeared first on Bitcoin Magazine.

Bitcoin may be touted as a global and accessible currency, but some of its users are being badly underserved.

Michael Staffen is a bitcoin user who is blind. He posted about his frustration with bitcoin wallets, which currently don’t offer any accessibility options to visually impaired people, on reddit:

“I am a fully blind person who uses a screen-reader and every bitcoin wallet I have downloaded is inaccessible to my screen-reader … This is making me very annoyed as I am a bitcoin supporter and I have acquired my own bitcoin, I just can’t goddamn use them without getting help from someone else.”

Staffen’s reddit post attracted nearly 200 comments and almost 1,000 upvotes. The comments were largely positive, calling on wallet developers to provide accessibility features for blind bitcoin users.

A core developer working on Multibit, a popular open-source wallet, said he raised the issue with the Multibit developer community and had started beta testing for accessibility issues after seeing the post. He has also recruited Staffen as one of Multibit’s beta testers.

Wallet accessibility

CoinDesk contacted Staffen to get a walkthrough of his experience using a bitcoin wallet with a screenreader. A screenreader is a piece of software that reads out the entire contents of a computer display and allows a blind or partially sighted person to operate the device.

“Most people want to make [bitcoin] accessible, they just haven’t considered it. That’s one of the problems around accessibility.”

Staffen uses the market-leading third-party application JAWS. As he fired up his computer, JAWS called out his cursor’s location on the screen.

Staffen said he uses only a keyboard to navigate through his computer. The screenreader read out each menu so quickly that Staffen had to slow it down for us to follow.

Firstly, he chose to demonstrate his problems with the the Bitcoin-Qt wallet. When the application launched, Staffen showed that he could only access the main menu bar in the application.

This menu bar contained three drop-down menus that allowed him to backup and encrypt his wallet, but did not allow him to perform basic functions like check his wallet address or send and receive bitcoin. Those features are accessed through buttons contained in the application’s main window.

“If I go to the Bitcoin-Qt wallet, I can get into menus like ‘file’, ‘help’ and ‘settings’, but I can’t really do anything with them. There’s nothing to [help me] hear what’s going on. There’s no interaction with the screenreader, so basically the wallet is useless to me, unless I get someone to help me.” He added:

“For example, even getting to the [wallet] address, which I need to cut and paste – I can’t even really do that.”

Staffen said his sister, who is also a bitcoin enthusiast, currently helps him access the wallet. However, Staffen says he’s not pinning blame on a particular company or person for the poor state of accessible wallets.

“Most people want to make it accessible, probably including the developers – they just haven’t considered it. That’s one of the problems around accessibility: It’s not that people intentionally exclude others. It’s also up to [people with disabilities] to make noise.”

Michael Staffen’s story

Staffen (pictured) is a 36-year-old who lives in a town called Regina in a relatively rural province called Saskatchewan, which is part of the ‘Canadian prairies’. He developed lymphoma, a cancer of the blood, four years ago.

When he was diagnosed, he was told he had stage-four lymphoma and that the cancer had spread to his central nervous system. He was given a bleak prognosis.

“I was in a coma for a total of a month and was given a 0% chance of living. When I woke up from my coma, I could not see or move.”

The cancer had damaged Staffen’s optic nerve, leaving him with no light perception. After a year-long stay in the hospital, where he received chemotherapy, he eventually started a physiotherapy regime to regain use of his body.

“I did physiotherapy twice a day, where I learned how to walk and use my body again. I am now considered cured!”

Staffen is currently enrolled at the University of Regina where he is studying for a master’s degree in public policy and administration. He expected to graduate in September.

He has also become active in the local technology scene, becoming a board member of a maker-space called Crash Bang Labs. When CoinDesk spoke to him, he was in the midst of monitoring his new litecoin mining rig.

Staffen got interested in bitcoin two years ago after hearing about it on a Canadian Broadcasting Corporation radio show, but was struggling to adapt to using technology as a blind person.

“As a relatively new blind person I just did not have the wherewithal to go about [buying bitcoin in 2011] and wiring money at the time just seemed extraordinarily shady.”

By April of last year, Staffen was comfortable enough with technology to give bitcoin another go.

“My sister and I teamed up to figure out how to buy bitcoins from Mt. Gox. We had to wire our money to Japan which seemed ludicrous and scary.”

Staffen was so enamoured with the digital currency that he used a cash advance from his credit card to get enough funds to buy some. Unfortunately for Staffen and his sister, they bought into the cryptocurrency at its April peak of about $250.

“The price collapsed the very next day. I kept them because I thought they may recover eventually,” he said. The cryptocurrency’s price, of course, rallied to over $1,000 over the course of the year. It’s currently about $850 according to the CoinDesk BPI.

MultiBit’s perspective

Gary Rowe, a core developer on MultiBit, said the team is working on a new version of the wallet that would implement the Java Accessibility API recommendations.

This set of guidelines is designed to help developers create Java applications that are accessible to people with disabilities, including visual impairment or blindness. Rowe said he expected MultiBit HD to be released by the end of March at the latest.

“MultiBit are committed to delivering code of the highest quality to a wide range of users. Some of those users require support for accessibility to make their experience of MultiBit better,” he said, adding that Staffen is MultiBit’s only visually impaired beta tester at the moment.

Assistive technology boom

Screenreader technology is becoming increasingly common on computing devices, led by a combination of consumer expectations, industry adoption and legislation, said Robin Spinks, the principal manager for digital accessibility at the Royal National Institute of Blind People, the leading charity in the United Kingdom.

The latest WebAIM survey of screen reader usage, for example, shows that adoption of the technology has grown from 12% to 72% in the last three years. WebAIM is a non-profit organisation focused on web accessibility solutions at Utah State University.

Apple developed a screen reader and made it standard on iOS in 2009, a move that Spinks says sparked mass adoption of the technology. He said:

“Apple has led the march on this and other companies are following in their wake. Leaders in industry are demonstrating that it’s economically viable.”

As for Staffen, he says he plans to immerse himself further in the bitcoin economy. He’s been thinking about developing an education centre for people to learn about bitcoin or a wallet that’s accessible to blind users.

“I’m not sure what the business will be yet, all I know is I want to make a living from it.”

Image via Shutterstock, Michael Staffen

Welcome to the CoinDesk Weekly Review 10th January 2014 – a regular look at the hottest, most controversial and thought-provoking events in the world of digital currency through the eyes of skepticism and wonder. Your host … John Law.

Everyone has friends they love but secretly fear because of what they might do. John Law has one such friend who is particularly dangerous during the festive season. Probably a CERN particle physicist in a previous life, she delights in finding people at parties who are polar opposites and accelerating them towards each other at great speed to see what bits fly off.

She has a particular talent at finding denialists – climate change, evolution, moon landing – and plumping them in front of the unfortunate Law, who finds them all as unappetising as toad-in-the-hole made with real toad. Of course, 2013 was the year of the bitcoin …

Thus, Dear Lord, thus:

“Bitcoin expert, eh? Criminals and drug-runners love it.”

“It’s a ridiculous speculation. I’d say ban it, but let the suckers hurt. Hahaha!”

“My friend says that millions of computers waste megawatts of electricity on that. It’s killing the planet,” and so on, and so forth.

If it’s not possible to escape by pretending to speak nothing but Esperanto, then a game attempt to engage in battle takes place.

The electricity nonsense is simple: agree that bitcoin mining does indeed soak up power, “but so much less than the real thing, eh?”.

As nobody has the faintest idea how much energy mining metal and running the financial system takes up, this is an easy bluff to carry off. And certainly true, to boot. As for the rest, John Law is glad to report that this week alone has provided two excellent counter-examples against the inherent badness of bitcoin – one very small, one very big. The very big one has made all the headlines: the very small one is far more significant. Let’s start with the very big.

Overstock steps up

Overstock.com is taking bitcoin. If you’re not in the US, you may not know Overstock – it’s an aggressive online Utah retailer that started in 1999 shifting bankruptcy, end-of-line and warranty return stock, but now does more general products.

What sets it apart from the thousands of other outfits that take bitcoin is its size, over a billion dollars a year in sales. While this is no Amazon – it’s actually roughly the same as Greggs the bakers – it’s by far the biggest single organisation to hook its wagon to the cryptocurrency star. It’s also the only one approaching a household name.

John Law suspects this is far more a publicity stunt than a major revenue move, but probably not a cynical one. The CEO, Patrick Byrne, is no supporter of the status quo and clearly relishes rewriting rule books – and won’t mind one bit if the threat of bitcoin manages to drive down the transaction costs from banks for more traditional fund movements.

What this is costing him isn’t known, but he’s bitcoin-enabling courtesy of Coinbase – who will be hoping hugely to benefit from this vote of corporate confidence. Who’d be surprised if a mutually advantageous deal was struck between the two outfits?

Ah yes, banks. The selfsame banks who’ve been quick to close down the accounts of individuals or small businesses discovered meddling in bitcoin. It’d be a bold bank indeed who rid themselves of a billion dollar business. And even for organisations that habitually show less shame than a medieval monarch, it’s going to be hard for them to take Byrnes’ bucks but shun the little guys. That sort of behaviour gets regulators quite irate.

Any way you cut it, Overstock’s practical involvement in bitcoin is of major significance in the progress of the feisty digi-dosh – and it’s only a week into 2014. What could be more exciting?

Strictly for the birds

Well, there’s the small case of TipperCoin. It doesn’t come much smaller. Started by two guys in San Francisco as an open-source project, it has just one purpose – to let people tip each other small amounts via Twitter.

Oh, and to get bitcoin more widely accepted. What it isn’t, is out to make any money or open new avenues of lawlessness or make ego-drenched superstars of its creators. This is important stuff, because it passes the two most significant tests of any innovation: do people want to do this, and could this be done any other way?

Clearly they do want to do this – there are already others working on making it better – and no, there is no other way of moving small amounts of money across Twitter, at least not without ludicrous amounts of complexity and expense that makes the whole business pointless.

This test isn’t met by the Overstock move – yes, people want to buy stuff from Overstock, but they can already do it with much less fuss and no particular extra expense through plastic or PayPal.

And at some point, there’ll be another Biggest Ever retailer, even bigger than Overstock, who’ll adopt the cryptocurrency. It’s a good story, but it doesn’t say much about bitcoin.

Back at TipperCoin, the nascent service is growing in some odd directions. One is the inclusion of Dogecoin, the mutant currency based around a bizarre, dog-themed Internet meme that John Law has already tipped for greatness. OK, mentioned in awe and incomprehension. That counts.

TipperCoin is already an offshoot itself, from work done previously in adding microtransactions to reddit usage, and because it’s open source and based in a lively community of skilled yet twisted developers, such mutations can be produced in days. With nobody in charge and no investors calling the shots, this thing could spread wherever people wish – and, in fact, will be a lot harder to shut down than anything more normally structured.

As principal perpetrator Scott Li said when asked if Twitter approved – don’t know, but we’re too small to matter. Such is the very spirit of bitcoin, and it’s this DNA which is the important core of the whole idea.

Will TipperCoin make a big difference? It might: we just don’t know what will happen when it’s painless to throw a couple of cents at somebody who made you laugh for a second through a clever tweet. It might sink without trace, and probably will, but an experiment that couldn’t have been done before has been attempted.

Which is how things change, after all.

Tea totals

A new bitcoin exchange, BuyBitcoin.ph, has officially launched in the Philippines.

Unlike many other exchanges popping up around the world, it is not headed by a couple of anonymous coders working out of a garage.

BuyBitcoin.ph, co-founded by four bitcoin enthusiasts from all corners of the globe, doesn’t want to be ‘just another exchange’. It appears the company is pinning its hopes on remittances, which makes a lot of sense. There are an estimated 2.2 million Filipino expats around the world, and last year they sent over $13.9bn back home. This is obviously a huge untapped market.

Where to buy

Filipinos looking to buy bitcoins can simply walk into one of 800 branches of the Bank of the Philippine Islands (BPI) and make a deposit. BuyBitcoin.ph is working to add a few more payment options, but so far the focus appears to be on good old fashioned cash.

However, since the focus is on remittance, most people will probably use the platform for bitcoin to fiat conversion. At the time of writing, the buy/sell exchange rate was 38,616.53/34,965.92 Philippine peso per bitcoin, which works out to $782/$864. At the same time, the CoinDesk Price Index stood at $850.

Remittance is just the beginning

BuyBitcoin.ph co-founder Lasse Olesen points out that the Philippines is one of the fastest-growing economies in Asia, and the third-biggest global market for remittances. Olesen told TechInAsia:

“Many online transactions here are being made by cash deposits in physical locations, and bitcoin is cash for the internet, so it’s a good fit. [It’s also] incredibly empowering for the self-employed freelancer or merchant.”

“It gives you instant access to a global market where you can receive payments practically for free and, if you want, exchange to cash locally. If you’re a small merchant, accepting international payments through PayPal or bank wires is just not feasible with their fees.”

Thanks to Bitcoin’s peer-to-peer network, remittances could be significantly cheaper and faster than traditional wire transfers, but to make it all a reality, a good local exchange is needed. This is what BuyBitcoin.ph is all about.

Philippines Flag Image via Shutterstock