The program I wrote uses 2*10^8 random numbers which are produced using rand. Is there a way to find if rand produces duplicates in my program? I found that RAND_MAX is equal to 2^31-1 in the machine I am using. Anna ----- Original Message ----- From: Ian Lance Taylor <iant@xxxxxxxxxx> Date: Saturday, August 6, 2011 10:01 pm Subject: Re: question on rand() > Anna Sidera <sidera.anna@xxxxxxxxx> writes: > > >>From this, can I find out when the numbers start repeating? How > can I find it? I cannot find the period using > > > > man rand > > This question really doesn't have anything to do with gcc. gcc > does not > provide a rand function. The rand function will come from your C > library, and gcc does not include a C library. > > If you are using GNU glibc, which is probably the case if you are > usinga GNU/Linux system, then rand is not implemented as a linear > congruential generator, and the period is quite long. See the source > code. > > Ian >
