[question] random number generator

[vieestchien]

Hello,

I am trying to generate a very large uniformly distributed pseudo-random number (around 15 digits, similar to Random.nextLong() in Java), the problem is that both rand() and random() only return int/long type (10 digits max).
Is there any way to generate pseudo-random number in long long int type?

Thank you.

[Salem]

Well if your rand() is say 16 bits, and you want 32 bits, you could do this unsigned long result = ((unsigned long)rand()) << 16 + (unsigned long)rand(); Just join 2 rands together.

For a much better random source, look at the boost library.
The standard rand() has no guarantees as to it's randomness (some implementations are horrible).

[tesuji]

Hi vieestchien

There is also famous Mersenne Twister MTRand by Makoto Matsumoto.

krs,
tesu