[thelist] Looping Psuedocode
Simon Willison
cs1spw at bath.ac.uk
Thu Aug 28 10:52:26 CDT 2003
Rob Smith wrote:
> Hi,
>
> I've struggled with this for quite some time now and still haven't found the
> best approach to this. Basically I want to see some Psuedocode that solves:
>
> from :: to ::
> Item A Item A
> Item A Item B
> Item A Item C
> Item B
> Item B
> Item B
> Item B
> Item C
> Item C
The answer to this very much depends on what technology you are using -
PHP for example has a built in function to do this. As pseudo code
(actually Python which is close enough) here's how I would do it:
fromArray = ['a', 'a', 'a', 'b', 'b', 'b', 'c', 'c']
toArray = [] # An empty array
for item in fromArray:
if item not in toArray:
toArray.append(item)
Donning my computer scientist hat for a moment (algorithm complexity
isn't a strong point of mine) I'd say that has at most quadratic
complexity, which is pretty poor. Off the top of my head though I can't
think of a better algorithm. For small data sets it should work fine though.
Cheers,
Simon Willison
http://simon.incutio.com/
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