Archive: February 28, 2024

 

Archive: February 28, 2023

hmm is the new so

Tuesday,  02/28/23  09:32 AM

Back in 2015 I noted So is the new Well.  As a bit of voice noise by way of introduction to saying something.  Courtesy of Shirley, I can now note, Hmm is the new So.

Hmm be it :)

 

 
 

Archive: February 28, 2022

 

Archive: February 28, 2021

 

Archive: February 28, 2020

 

Archive: February 28, 2019

 

Archive: February 28, 2018

 

Archive: February 28, 2017

 

Archive: February 28, 2016

Codility ... testing, testing, 1 ... 2 ... 3

Sunday,  02/28/16  11:01 AM

Recently a potential client asked me to take a coding test on Codility.  (Well, they asked "us", not knowing that "us" was me :)  I took the test and failed miserably.  Herewith, lessons learned...

At right: the Codility interface ... (click to enbiggen)

My first mistake was taking the whole thing lightly.  I'm a great C++ programmer (if I say so myself) so I was confident in my ability to code.  However, there is more to passing a Codility test than writing good/great code.  1) you have to understand the interface, 2) you have to code an efficient solution, as opposed to a simple one that works, and 3) you have to do it in a limited amount of time.  Oh, and 4) you have to pay attention to boundary conditions.

1) To understand the interface, Codility recommend you take their sample test.  This is good advice which I did not take.  The interface is just fine, but it does take a few minutes to acclimate to it, especially the means of entering and running test cases.  In particular, they allow you to run any test cases you want, but they do not tell you whether the tests get the right answer, only whether they compile and run.  This isn't immediately obvious, and it's important.

2) Codility specify the O-notation of the expected best solutions.  Most of their algorithmic problems are pretty simple, but coming up with a most efficient solution may require tricks.  It's a mistake to go after a tricky / efficient solution first, however, as I found to my chagrin.  As I note below, code a simple solution that works first, then develop optimizations.

3) You are typically given 30 minutes to complete a test (I was given 90 minutes to complete three).  This is plenty of time to code and test a simple algorithm.  However, it is not plenty of time if you spend a lot of it learning the interface and investigating interesting optimal solutions.  Plan your time wisely.  Out of 30 minutes I suggest 10 minutes for a bolt dumb solution, 5 minutes creating a wide variety of test cases, and 15 minutes for optimization.

4) In many of their tests (I have now taken six) Codility specify boundaries like "integer in the range -2,147,483,647 ... +2,147,483,647.  You will recognize these are the max values for a 32-bit int.  They will give you these values in a test case.  If you want to add 1 to such an int, you'll need a long long.  This sort of stuff doesn't often come up in everyday coding, but you need to be ready for it.

My suggestions for anyone taking a Codility -type test:

  • Take a sample test or two first, to get used to the interface.  This post discusses their sample problem (take that one first) and has links to two others.
  • Develop your solutions in your favorite IDE, and then copy-and-paste them into Codility.  Really really.  At first you will think "this interface is fine, no worries" (as I did), but when you're pressed for time and want to run many test cases, you'll be happy to have your own IDE.  Mine is Visual Studio, yours might be Xcode or Eclipse, but use it.
  • For each problem, develop the absolute most bolt-dumb simple solution first.  Make sure it works (with "printf" debugging, or whatever), and then use it as a check against your more complicated more efficient solutions.  This does two things for you: 1) if you run out of time, you have a solution that works, 2) having an instant test for any would-be more-efficient solution is most helpful.  You can run though many, many possible optimizations rapidly once you have an automated test.

In addition to Codility, other sites which offer these types of tests include TestDome and HackerRank.  They're actually a lot of fun once you get into the mode of taking them.

A final comment: In Googling I found quite a few people online have commented that this type of test is a bad measure of programming ability.  Okay, I agree it isn't perfect, and of course you will want other data points before hiring someone.  But it's a pretty good screen; ideally a good programmer would pass such a test, easily (*ahem*), and the fact that they've taken the time to do so is an indication of their sincere interest in your opportunity.

Cheers, and happy testing!

 

 
 

Archive: February 28, 2015

Saturday,  02/28/15  08:05 PM

So.  (Is the new "well")
So be it.

Ahead of the impending announcement and availability of Apple Watch, a slew of competitors are announcing products.  Including Pebble, with the new Pebble Time.  Yay.  


Meanwhile Swatch have announced the ... Touch Zero One.  Bad name but looks interesting.  


And there is a WebOS-based LG Watch Urbane, which looks kind of cool.  (I was a big fan of WebOS on the Palm Pre, but it isn't clear how that translates to a smartwatch UI.)  


And LBNL, Huawai have announced a nice Android Wear smartwatch.  

Lots of choices, but I think everyone is going to wait and see what Apple announce before buying anything... 

 

 

Moses awaits

Saturday,  02/28/15  09:24 PM


Hehe I love it

 
 

Archive: February 28, 2014

ready, set, Iditarod

Friday,  02/28/14  10:51 PM

So, are you ready for some sled dog racing

Tomorrow is the start of the 2014 Iditarod race from Anchorage to Nome, Alaska, celebrating a famous delivery of medicine via dog sled.  Iditarod itself is a tiny Eskimo village about halfway along the 1,000 mile route.  In recent years the race has alternated between a Northern and Southern route; 2014 is an even year and hence the mushers are taking the Northern Route this year.

Although the race "starts" tomorrow, it is only a ceremonial event with each musher parading through the streets of Anchorage; the true race starts on Sunday, from Willow, and then continues on for 975 miles.


Each musher starts the race with a team of sixteen dogs and must finish with at least five dogs.  (Dogs are typically "dropped" at the various checkpoints, due to injuries or because they are tired or under-performing; every dog is examined by a veterinarian at every stop.)  Each team must make one 24-hour stop along the way, and two 8-hour stops; when and where to take stops is a key point of strategy.

There are sixty-nine teams starting the race tomorrow, and I am of course rooting for DeeDee Jonrowe, pictured with her team above right.  DeeDee has competed in the Iditarod since 1980 and has finished in the top ten fifteen times, including last year.  Go DeeDee!

(All Iditarod 2014 posts)

 

cancer galaxy

Friday,  02/28/14  11:24 PM

 

a painting of cancer cells, inspired by Carl Sagan

lovely
(click to enbiggen)

 

 

Friday,  02/28/14  11:49 PM

Whew, what a day.  Great all-day meeting which extended over dinner ... I'm exhausted from spending so much time with so many people who are smarter than I am :)

Check out Time in Motion: animated photo collages that show many different times of the day all at once.  What a cool idea.  [ via Laughing Squid

Ever wonder Where Time Comes From?  Well now you know.  [ via Little Green Footballs

AppleTV 'difficult to call a hobby' after $1B in sales last year.  Somehow this does not surprise me.  I've been an AppleTV fan for years, and have wondered why they have not been adopted more broadly.  I guess it just took some time :) 

TechCrunch: a few thoughts on Free Windows.  Yeah, with OSX now free from Apple, Android and Chrome free from Google, and Linux free entirely, it will be increasingly more difficult for Microsoft to keep charging OEMs (and us) for Windows.  This has to be figuring into their thinking, as they ponder becoming MobileSoft... 

Answering the tough questions: Why programmers work at night.  Okay, maybe that isn't really a tough question. 

From The Verge: IOS, a visual history.  Shows exactly how we got tothe pinnacle (IOS 6) and are now descending the far side (IOS 7)... 

'Travelers', by Bruno Catalano, overlooks the harbor at Megeve.  "For people in search of themselves"!

 

 
 

Archive: February 28, 2013

 

Archive: February 28, 2012

 

Archive: February 28, 2011

 

Archive: February 28, 2010

world's proudest Dad

Sunday,  02/28/10  09:31 AM


What can I say?
Yes, we had a great time :)

 
 

Archive: February 28, 2009

pathologist's cockpit

Saturday,  02/28/09  08:30 AM

Check this out, perhaps the ultimate multi-monitor setup of all time, intended for programming:

Here we have four 24” full-page monitors in portrait mode, flanking two 30” monitors in landscape mode.   The hard part would be the video cards and drivers to make this work…

As useful as screen real estate is for coding, it is even more useful for viewing digital slides, and so naturally I couldn’t help extrapolating to this:

Just when you think you’ve seen everything, you realize “everything” is so much more than you thought :)

 
 

Archive: February 28, 2008

Thursday,  02/28/08  10:51 PM

I'm still coding - still trying to deliver something due a week ago.  The key issue is adapting to an industry "standard" which turns out to be, well, wiggly.  Maybe more when I'm done, but in the meantime I can briefly poke my head out and see that it's all happening...

One thing that's happening - we're in a recession.  So be it, it happens.  Why is everyone trying so hard not to call it like it is?  The sooner we absorb it, the sooner we'll recover.  And yes, we will recover. 

From the New Yorker's Annals of Science: The Numbers Guy.  "According to Stanislas Dehaene, humans have an inbuilt "number sense" capable of some basic calculations and estimates. The problems start when we learn mathematics and have to perform procedures that are anything but instinctive."  This is one reason why charts (like the one at right) at so helpful; they work around our prejudices. 

Katherine Mangu-Ward observes The Obama Campaign is full of economists, and yet "according to a new L.A. Times/Bloomberg poll, people think McCain will do a better job handling the economy than Obama".  I agree with Glenn Reynolds that maybe there's no contradiction here...  

I predict that this fall the economy will be a bigger topic of discussion than Iraq, as oil hits $103 a barrel.

The annual TED conference is taking place, and one of the presenters was Susan Blackmore, author of The Meme Machine, which happens to be one of my favorite books, ever.  "First replicators were genes. Then memes. We now have temes (tech memes) are a third replicator on our planet."  How excellent - I would have loved to see her.  She is a fantastic source of new memes - about memes :) 

I love this: Mark Pilgrim on Jumping out of the System.  In which Gödel, Escher, Bach is used to explain why strict XHTML parsing doesn't make sense :) 

Russell Beattie doesn't think much of Chris Anderson's latest insight (Free).  At least he knows why he keeps getting wired.  "While reading it, however, I was reminded of the fact that I didn't renew my Wired subscription last year, and yet, I still receive the magazine every month. It's nice to see Chris is practicing what he preaches. :-)"  Personally, although I think Free is important, it isn't as insightful as The Long Tail... 

Jeff Atwood thinks we shouldn't listen to our users.  His three rules of usability: 

  1. Watch what people actually do.

  2. Do not believe what people say they do.

  3. Definitely don't believe what people predict they may do in the future.

Scott Loftesness thinks the iPhone is entering from below.  "Reading this WSJ blog post about Apple's scheduled iPhone briefing next week with a focus on the enterprise, I was struck by how the iPhone just might be a very useful entry strategy for pursuing enterprise opportunities."  Huh.  Could be... 

Did you watch the Academy Awards last Sunday?  Me neither.  Nobody does anymore.  Weirdly, I know quite a few people (mostly women) who watched the Oscar pre-game, to see what everyone was wearing, but the show itself has totally jumped the shark. 

Here we have the quadruple layer bike.  Wow.  That's just about all I can say. 

The original Photoshop icon.  How excellent!  Much better, in my humble opinion, than the current one...  [ via Daring Fireball

 

 

 
 

Archive: February 28, 2007

 

Archive: February 28, 2006

 

Archive: February 28, 2005

masters of the universe

Monday,  02/28/05  10:45 PM


Masters of the Universe
Albert Einstein and Kurt Gödel

The 2/28 issue of the New Yorker has a terrific article entitled "Time Bandits", about Albert Einstein and Kurt Gödel.  Well it is really a review of John S. Rigden's new book, “Einstein 1905: The Standard of Greatness", and Rebecca Goldstein's biography “Incompleteness: The Proof and Paradox of Kurt Gödel”.  (Both of these books seem interesting and well worth reading.)  The review is a wonderful overview of these two amazing men and their improbable friendship, as well as their shared quest to understand the nature of time.

 
 

Archive: February 28, 2004

 

Archive: February 28, 2003

Friday,  02/28/03  06:39 PM

Last day of February already!  Where is 2003 going?  Whew!  And this makes two months Critical Section has been in business.  We've served 1994 visitors of whom 310 have returned at least three times.  That is so cool, thanks!

Charles Krauthammer nails it: A Costly Charade at the U.N.

So again the America's Cup is postponed; after working through the night to rig a new mast, TNZ was not able to test it against Alinghi today.

Well, another dot-com shoe has dropped; the Red Herring has closed its doors.  It joins Upside, the Industry Standard, eCompany, and Forbes ASAP, leaving Business 2.0 as the last "new economy" business magazine still publishing.  I can distinctly remember early 2000, when Red Herring was about 500 pages thick, choked with tombstone ads from investment banks, and full of "we're too cool for ourselves" articles.  I found this great article about all the contenders in Forbes ASAP, dated August 2000 - good for a trip down memory lane...

In an interesting article, FastCompany asks Which Price Is Right?

Here's another wrinkle is my browsing experience - today I'm trying Opera.  So far it seems to combine the speed of IE with the pop-up killing and cookie management of Mozilla.  It might even be faster than IE.  It does not seem to know when to reload dynamic pages, though...  Stay tuned...

[Later - no dice.  We have two show stoppers - ads in the header (or pay $40), and trouble rendering sites with complicated CSS.  That's why I stay away from CSS layouts - but a lot of people use it now.  And they test with IE and Mozilla.  Too bad, because Opera sure is fast.]

If you want to laugh, please read The Horror of Blimps :)