[Qt-interest] [SOLVED] Is it a stupid way for sorting?

[M. Bashir Al-Noimi]

Cooooool, QMultiMap fix the issue thanks for you guys ;-)

On 22/04/2010 08:03 ص, Malyushytsky, Alex wrote:
> There is no point in sorting any data using widget.
> I think you should review help on
> void qSort ( RandomAccessIterator begin, RandomAccessIterator end, LessThan lessThan )
> in Qt documentation again.
> I think it contains pretty good explanation.
>
> The code below should do the job,  but it is not very efficient
>
> bool myCompareFunction(const QString&s1, const QString&s2)
> {
>       return s1.count("?")<  s2.count("?");
> }
>
> QStringList sortPatterns(QStringList patterns)
> {
>       qSort(patterns.begin(), patterns.end(), myCompareFunction);
>
>       return patterns;
> }
>
> It is not very efficient cause every time qSort need to compare 2 values it will recount "?".
> Better approach might be to compute it only once.
>
> You might use QMap or build another container like QList<int, QStringList::iterator>  and sort it
> with above mentioned technique,  ( int value will be a count and iterator will give you access to the string . You can use index instead of iterator )
>
> Example of using map for sorting in your case:
>
> QStringList sortPatterns2(QStringList patterns)
> {
>       QMultiMap<  int, QString>  map;
>
>       for(int i=0; i<patterns.count(); i++)
>       {
>            int count = patterns[i].count("?");
>            map.insert( count, patterns[i] );
>       }
>
>
>       return map->values ();
> }
>
> Regards,
>          Alex
>
>
> -----Original Message-----
> From: qt-interest-bounces at trolltech.com [mailto:qt-interest-bounces at trolltech.com] On Behalf Of M. Bashir Al-Noimi
> Sent: Wednesday, April 21, 2010 7:12 PM
> To: qt-interest at trolltech.com
> Subject: Re: [Qt-interest] Is it a stupid way for sorting?
>
> Thanks William,
>
> Actually I took this way because I don't know how I can make sort
> process by qSort (I found in Qt documentation something about QMap and
> qSort), so could you give me an example explains how to do that?
>
> On 21/04/2010 07:58 م, william.crocker at analog.com wrote:
>    
>> See:
>>
>>        qSort ( RandomAccessIterator begin, RandomAccessIterator end, LessThan lessThan )
>>        et. al.
>>
>> M. Bashir Al-Noimi wrote:
>>
>>      
>>> Hi All,
>>>
>>> I want to sort QStringList by specific item count so I tried to use QMap
>>> for it but I failed but I used QTableWidget instead but without viewing
>>> it in the GUI, *is it correct way for sorting? it's slow (and stupid :-[ )?*
>>>
>>> QStringList sortPatterns(QStringList patterns)
>>> {
>>>       QStringList result;
>>>       QTableWidget *table = new QTableWidget(patterns.count(), 2);
>>>       for(int x=0; x<patterns.count(); x++)
>>>       {
>>>           int count = patterns[x].count("?");
>>>           table->setItem(x, 0, new QTableWidgetItem(QString("%1").arg(count, 2, '0')));
>>>           table->setItem(x, 1, new QTableWidgetItem(patterns[x]));
>>>       }
>>>       table->sortItems(0);
>>>       for(int x=0; x<patterns.count(); x++)
>>>           result<<table->item(x, 1)->text();
>>>       return result;
>>> }
>>>
>>>
>>>
>>> --
>>> Best Regards
>>> Muhammad Bashir Al-Noimi
>>> My Blog: http://mbnoimi.net
>>>
>>>
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>>>
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>>      
> --
> Best Regards
> Muhammad Bashir Al-Noimi
> My Blog: http://mbnoimi.net
>
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-- 
Best Regards
Muhammad Bashir Al-Noimi
My Blog: http://mbnoimi.net