Random Number Generation

[Harsha Vardhan]

Is there a function in MFC to generate a random number that is LESS
THAN a user-defined upper limit?

When I used to program in Turbo C I had used such a function. But in
MFC, I see that there are only functions that generate random numbers
between a LOWER limit and the constant RAND_MAX (which I can't change
anyway). I cannot set the upper limit.

I am looking for a method other than comparing each generated random
number with the upper limit & discarding bigger numbers.
Thanx a lot.

[peterchen]

Hi,

rand() % 6
will generate random number 0..5

Note that rand() is not useful for statistical purposes - and the modulo makes it worse (a bit). But if it just should 'look random', or it is for a game or something, it#s fine.

Peter

[William Yowell]

// No such luck.
// Try this trick.

LONG SomeClass::Random(LONG nMin, LONG nMax)
{
// use modulus to return range then add nMin to move to offset.
return rand() % (nMax-nMin+1) + nMin;
}

[Philip Nicoletti]

srand((unsigned)time(NULL));

// Generate random number within the range : 0 to iMax

int iMax = 250;

int newRan = rand() % (unsigned)(iMax+1);

[Harsha Vardhan]

Thanks a lot for the help guys.
Really appreciate it.