All entries for Thursday 09 January 2020

January 09, 2020

Finding The Solution

New Year, New blog post. Just a short one this time, following on my my post on FizzBuzza few months ago. Even a problem as simple as that can be solved in myriad ways, and as I program more and in more languages, I find myself less often wondering how I can solve a problem, and more often how I should.

Most of the languages I work with let me solve problems using the basic command structures, and, as I wrote about last time in The X-Y problemit can be hard, but is vitally important, not to get confused by your partial solution and miss a better one.

Recently I've been learning Perl to do some complex text-processing, and find it to be a drastically different way of thinking to my C/Fortran background. It's tricky to think in terms of text matches and substitutions when I am so used to thinking of the position of each character in a string and working in terms of "index-of-character-X plus 1" (similar to working in terms of for-each loops when one has only used for). For the processing being done, the proper Perl solution is much shorter, easier to understand, etc, although it takes me a bit longer to produce initially.

A recent Stack Exchange post I saw had somebody asking why his boss didn't appreciate his brilliant coding techniques, because design patternswere second nature to him, and his boss wanted to use far simpler solutions. He probably came back to Earth with a bit of a bump when it was firmly pointed out that "patterns being second nature" was actually a bad thing, because it rather sounded like he trotted out the first "pattern" he could think of, instead of actually thinking about the problem he was solving. Nothing wrong with the patterns themselves, but critical thinking is required to decide whether they are suitable, optimal etc.

The other common mistake people make is demonstrated in Terry Pratchett's description of "Death's Swing" (e.g. https://en.wikipedia.org/wiki/Death_(Discworld)#Home), which mirrors the Sunk Costs fallacy. Trying to build a swing for his Grandaughter, the character of Death plows forward inspite of all problems. He hangs the swing from the two strongest branches. These being on opposite sides of the tree, he cuts away the trunk, shores it up and ... This can easily happen when programming and the trick is never to be afraid to throw away (or file away for future use) a solution, even a good one which took a long time, if it stops fitting the problem. In Death's case, it is less because he is unwilling to throw away the work already done, and more an issue of very linear thinking, but the effect is the same.

Hopefully this is already obvious, and you always think before you code, happily refactor or rework your own code, and have an ever-growing solution bank to call on. I suspect very few people are willing or able to throw away all the false starts they probably should though. Just keep in mind that there is a crucial difference between "what solves the immediate problem" and "the code I should probably actually write", and strive for the latter.

January 2020

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