Hi, Thank you very much. It worked fine. I had to include the necessary header files.
On Fri, Jun 25, 2010 at 8:52 PM, Sharad Birmiwal <[email protected]>wrote: > On Fri, Jun 25, 2010 at 10:03 AM, Pushparaj Shetty <[email protected]> > wrote: > > Hi, > > I need to generate random number to assign weights to graph edges. Using > > rand() will give same random sequence on every run. Kindly tell how to > > generate distinct random for every run. > > In Borland C there is randomize()? whats is the equivalent here? > > You can use srand(unsigned int seed) to choose the randomization seed, > if that's what you want. To get a unique random sequence every time > you start your application, this is what I'd suggest (this is what I > do, a dirty hack): > > (I'm writing this on the spur of the moment, just take the idea and > code it yourself); > > unsigned int seed; > fd=open("/dev/random", RD_ONLY); > read(fd, &seed, sizeof(seed)); > close(fd); > srand(seed); > > > What this approach essentially does is take the seed from this file > called "/dev/random". From the name, I have always guessed that > everytime you read /dev/random, it generates random input. > > What I hope is happening is that "/dev/random" gets affected by > "noisy" inputs like frequency of keyboard usage, mouse behaviour etc > (these things are not unheard of, may be they happen if you have the > hardware generators). This random sequence generator might also be > taking inputs like variation in CPU temperature or disk usage to > "truly" randomize itself. > > On a side note, one resource you might want to dig into is random > number generation by gnu scientific library (gsl)[1]. > > > Hope this helps, > Sharad > > > [1] > http://www.gnu.org/software/gsl/manual/html_node/Random-Number-Generation.html > > -- > l...@iitd - http://tinyurl.com/ycueutm > -- Pushparaj Shetty D. IIT Delhi Cell# 9716616748 -- l...@iitd - http://tinyurl.com/ycueutm
