[Year 12 SofDev] An algorithm puzzler for your kids (and you?)

[Timmer-Arends]

Mark, you're probably right but two chick-flicks on the telly and out 
numbered 2 to 1....

Regards
Robert T-A

----- Original Message ----- 
From: "Mark Kelly" <kel at mckinnonsc.vic.edu.au>
To: "Year 12 Software Development Teachers' Mailing List" 
<sofdev at edulists.com.au>
Sent: Saturday, March 10, 2007 8:28 PM
Subject: Re: [Year 12 SofDev] An algorithm puzzler for your kids (and you?)


> O, Robert!  You really ought to take Margaret out dancing.
>
> Sitting in the dark running 100 million algorithm iterations on a Saturday 
> night can't be much fun!
>
> :-)
>
> Mark
>
> Timmer-Arends wrote:
>> Hello Mark and Robert
>>
>>> Robert Hind wrote: =(ROUNDUP(n*4,0)/4)
>>> Mark Kelly wrote: =(-INT(-n*4)/4)
>>
>> I switched Excel to manual recalc then created a small macro that in 
>> effect
>> presses F9 (recalc) one million times.
>> The results for 5 runs each:
>> RH: 32.31s, 34.37s, 30.10s, 34.48s, 33.86s
>> MK (student?): 33.98s, 33.98s, 34.12s, 34.72s, 34.86s
>>
>> Given that Excel runs in a multitasking environment where goodness knows
>> what other processes get a look in while the calcs are happening probably
>> explains the slight variation in times, but I'd say there's not much 
>> between
>> the two.
>>
>> Just for interest I dragged out an old copy of TurboPascal. Because it 
>> runs
>> in DOS mode times were much more consistent:
>> Also I could only try out the INT version since TP doesn't have a RoundUp
>> function.
>> The result: 100 million iterations (yes 100 million): 43.9s
>>
>> That makes Excel in the order of 100 times slower than compiled code! 
>> (and
>> that's old 8086 code what's more.) Just goes to show the overheads in 
>> Excel
>> and Windows generally.
>>
>> It would be interesting to get some times for a compiled VB program.
>>
>> Regards
>> Robert T-A
>> Brighton SC
>>
>>
>> ----- Original Message ----- From: "Mark Kelly" 
>> <kel at mckinnonsc.vic.edu.au>
>> To: "Year 12 Software Development Teachers' Mailing List"
>> <sofdev at edulists.com.au>
>> Sent: Friday, March 09, 2007 5:40 PM
>> Subject: Re: [Year 12 SofDev] An algorithm puzzler for your kids (and 
>> you?)
>>
>>
>>> 3 solutions for the price of one!
>>>
>>> Just goes to show the many ways an algorithm can take shape.
>>>
>>> Would be interesting to iterate each one a million times to compare
>>> relative execution speeds...
>>>
>>
>>
>> _______________________________________________
>> http://www.edulists.com.au
>> IT Software Development Mailing List kindly supported by
>> http://www.vcaa.vic.edu.au - Victorian Curriculum and Assessment 
>> Authority and
>> http://www.vitta.org.au  - VITTA Victorian Information Technology 
>> Teachers Association Inc
>>
>>
>
> -- 
> Mark Kelly
> Manager - Information Systems
> McKinnon Secondary College
> McKinnon Rd McKinnon 3204, Victoria, Australia
> Direct line / Voicemail: 8520 9085
> School Phone +613 8520 9000 << new number!
> School Fax   +613 9578 9253
>
> Webmaster - http://www.mckinnonsc.vic.edu.au
> IT Lecture notes: http://vceit.com
> Moderator: IPM Mailing List
>
> Doctor - We must all face reality sooner or later.
> Dowd   - I wrestled with reality for 35 years, doctor, and I'm happy to 
> say I won out over it.  ('Harvey', 1950)
>
>
> _______________________________________________
> http://www.edulists.com.au
> IT Software Development Mailing List kindly supported by
> http://www.vcaa.vic.edu.au - Victorian Curriculum and Assessment Authority 
> and
> http://www.vitta.org.au  - VITTA Victorian Information Technology Teachers 
> Association Inc