Qt and random numbers

tucnak · wrote on 10 Nov 2011, 11:43

Hi, Qt Developer Network!

My project have to create random "Shultz tables":http://www.st.vstour.info/ShultzTables.html

So it is my first try with qrand() and qsrand().

Can you help me and write howto write a code that will generate random number in diapason 1-25?

Thanks!

veeeee_d · wrote on 10 Nov 2011, 11:52

http://doc.qt.nokia.com/latest/qtglobal.html#qrand

tucnak · wrote on 10 Nov 2011, 12:34

I know it. I want to generate numbers in some diapason with special seed.

dangelog · wrote on 10 Nov 2011, 12:48

I'm not sure what that means (special seed?). Could you elaborate a little bit?

fluca1978 · wrote on 10 Nov 2011, 13:30

Not sure what you need, I guess a random number between 1 and 25. I don't know if there is a way to limit qrand (different from MAX_RAND), but maybe you can iterate over qrand to get a limited value?

cincirin · wrote on 10 Nov 2011, 13:52

[quote author="fluca1978" date="1320931836"]... but maybe you can iterate over qrand to get a limited value?[/quote]
In this situation the best method, in my opinion is:
@
qrand() % 25 + 1
@

veeeee_d · wrote on 10 Nov 2011, 14:03

Well I thought that solution was implied, my bad.

ardhitama · wrote on 10 Nov 2011, 17:21

You just need to implement your own nSeeder, try to start from getting current time's second.

@
qsrand(nSeeder);
inline int rangedRand(unsigned int min, unsigned int max){
return (qrand() % (max-min)+1) + min;
}
@

fluca1978 · wrote on 11 Nov 2011, 07:34

Good solution!

rentner323 · wrote on 17 Sept 2014, 08:19

Sorry for my post into such an old thread, but it must be:

@inline int rangedRand(unsigned int min, unsigned int max){
return (qrand() % (max+1-min)) + min;
}@

ardhitama · wrote on 17 Sept 2014, 09:56

[quote author="rentner323" date="1410941949"]Sorry for my post into such an old thread, but it must be:

@inline int rangedRand(unsigned int min, unsigned int max){
return (qrand() % (max+1-min)) + min;
}@[/quote]

Correct, curse me for the bracket