On Fri, Sep 03, 2004 at 08:37:20PM -0600, Jonathan Turkanis wrote:
2. tutorial docs:
The first code example: s[z] = (char) (rand() * 256 / RAND_MAX); I think this causes overflows way too often. s[z] = (char) (rand() % 256); is more likely intended even if it adds small bias.
Please no, this is in every FAQ on the use of rand(). The lower bits of rand() are not very random and using (rand() % 256) would be a classical case of misuse of that function. The use of (rand() * 256 / RAND_MAX) is fine because RAND_MAX can be devided by 256. For the general way one is supposed to devide the result of rand() in buckets. Ie, if you want to find an integer random number in the range [0, n> then you'd devide the results of rand() into n equally sized buckets and ignore results that fall outside of them in order to get a good distribution namely, while ((res = (rand() / (RAND_MAX / n))) == n); -- Carlo Wood <carlo@alinoe.com>