topic Re: Coffee Break Coding Challenge in BreakPoint

Coffee Break Coding Challenge

ChrissyC — Wed, 21 Mar 2012 13:19:53 GMT

I really enjoyed having a go at Jcarmody's FizzBuzz Challenge a couple of weeks ago.

It was a bit of a distraction during a lunch break, but more importantly seeing other peoples solutions gave me new insight on how some functions operate.

So i'm posting a new Coffee Break Coding Challenge (fanfare please! ).

The challenge is supposed to be a simple 5-10 min puzzle (but some Knights might struggle to make it last 5 - 10 secs ), hopefully producing some varied solutions that we can all learn from.

If this takes off and enough people enjoy it, perhaps we could make a regular feature. Anyway I'm getting ahead of myself; so here is the first Challenge:

"For any number, find the next highest number that uses all of the same digits. E.g. The next highest number after 123, using all the digits 1, 2 & 3, is 132."

-CC

p.s. Post your solutions in a spoiler box to avoid sending people down the same path as you!

Re: Coffee Break Coding Challenge

altenbach — Wed, 21 Mar 2012 14:54:14 GMT

Interesting. I probably won't have time for this before the weekend.

Anyway, what are the limits on "any number", does it need to fit in one of the integer data types or can it have a near infinite number of digits?

Is the input number a decimally formatted string?

Re: Coffee Break Coding Challenge

Ben — Wed, 21 Mar 2012 15:02:58 GMT

And since I am doing a stand-up coding routine let me ask...

THe input value will be assumed to have a larger available eg 321 ?

Ben

Re: Coffee Break Coding Challenge

ChrissyC — Wed, 21 Mar 2012 15:06:01 GMT

I did think about putting in strictly defined conditions on the input number, but I thought this might limit the creativity of some solutions.

A basic program might consider that only integers data types are allowed, but a more complex one would consider alternatives.

I guess my answer would be that it is up to you to define what "any number" means and either state the conditions your solution works for or impliment controls to ensure that people can't break it!

-CC

p.s. If this is too vague then we could easily introduce type definitions into the challenge description

Re: Coffee Break Coding Challenge

altenbach — Wed, 21 Mar 2012 15:08:31 GMT

As ben pointed out, there are quite a few numbers that don't have a solution. (321, 555555555555555555, etc.)

Re: Coffee Break Coding Challenge

ChrissyC — Wed, 21 Mar 2012 15:16:39 GMT

Ben, Altenbach

I realised this when I was going to use 321 as the example in the challenge description!

I would say that it's the programmers responsibility to check that an input will function correctly with his/her programme and alert the user if it won't.

-CC

Re: Coffee Break Coding Challenge

JÞB — Thu, 22 Mar 2012 03:08:05 GMT

are we limited to decimal digits or limited by non-duplicated digits in any place? (eg. for "123" would 1123 be a valid solution? This, I believe but do not wish to prove mathematically today, would theoretically unbound the solution by allowing 123, 1233, 123.3, 123.23, ad nasuem as member of the set solving the problem )

Love these types of posts! Really tough to pose these problems! noobs do it better

If you can pose these problems.... I would love to play! I'm just not sharp enough to forment the questions. Really (I do puzzles often, and really like the problem solving... I do not author puzzles. That takes a skill set I lack)

123.1

Re: Coffee Break Coding Challenge

ChrissyC — Thu, 22 Mar 2012 09:19:33 GMT

Right ok guys, this is all my fault for not properly defining the challenge (surely this never happens in the real world! )

So now i'm going to redefine the problem:

Your task (should you choose to accept it) is to produce a piece of code that will accept any integer input and calculate the next highest integer that uses all of the same digits.

Limits:

only integer numbers can be inputted or returned.
each digit can only be used once. e.g for 123 the next highest is 132, you cannot use the 1 twice to give 131.

Cue the A-team music and good luck!

Re: Coffee Break Coding Challenge

tst — Thu, 22 Mar 2012 11:44:29 GMT

OK, so here is a baseline - the stupid, brute force approach. No math, no elegance, just a quick and dirty solution, which seems to work correctly. It even handles duplicate digits, but it only works with positive integers.

Re: Coffee Break Coding Challenge

ChrissyC — Thu, 22 Mar 2012 13:35:27 GMT

Here's my crack at this, done over lunch.

I'm sure there are much more elegant ways of doing the maths and sorting the arrays etc. so comments/improvements on any pieces of code in this thread here would be a great help to everyone.

I confidently expect to see this re-posted in the Rube thread

You're going to have to excuse the wiring - I've still got a giant sandwich to get through before the lunch hour is over!

-CC

Re: Coffee Break Coding Challenge

JÞB — Thu, 22 Mar 2012 14:04:32 GMT

Not even coding it! .... Integer to "String", String to byte array, For each element in array build new array with the remaining elements sorted(split array, sort array), New array to string, Sort String Array, Threshold New array as String. Threshold index rounded up {to get the next higher} Scan String %d.

Isn't ASCII fun?

Re: Coffee Break Coding Challenge

IanC_ — Thu, 22 Mar 2012 15:12:09 GMT

Another attempt (shaped by an irrational aversion to strings).

Ian

Re: Coffee Break Coding Challenge

Thoric — Fri, 23 Mar 2012 12:28:18 GMT

I enjoy a good challenge, but I think I over-thought this one...

Re: Coffee Break Coding Challenge

Thoric — Fri, 23 Mar 2012 14:08:08 GMT

Unlike my previous solution, which is brute force, this one intelligently considers the numerals of the provided number. It is much quicker, however I expect that it has already been created in one of the spoilers by someone else because it is far from profound.

Excuse the icon

Re: Coffee Break Coding Challenge

Darin.K — Mon, 26 Mar 2012 04:15:56 GMT

Another excuse for the good, old and I mean 700 years old, method of Narayana Pandit.

Re: Coffee Break Coding Challenge

Ben — Mon, 26 Mar 2012 12:35:20 GMT

@Darin.K wrote:

Another excuse for the good, old and I mean 700 years old, method of Narayana Pandit.

Inplace operations used in the 14th Century?

I realize memory used to be a scarce resource but then again... "There is nothing new under the sun." Eclesiastes

Ben

Re: Coffee Break Coding Challenge

LV_Pro — Mon, 26 Mar 2012 15:02:31 GMT

I was trying to run this in LabVIEW 1345 with highlighting on, but the illuminated diagram on the parchment didn't change

Re: Coffee Break Coding Challenge

Ben — Mon, 26 Mar 2012 15:11:39 GMT

Did you try it with a 1.2 Candle power candle?

Some of those examples could only be realized uisng an upgraded candle.

Ben

Re: Coffee Break Coding Challenge

LV_Pro — Mon, 26 Mar 2012 16:40:19 GMT

I had forgotten to renew my SSP, so I didn't get the upgrade that year.

Re: Coffee Break Coding Challenge

jcarmody — Mon, 26 Mar 2012 18:01:38 GMT

Brute force: