Thanks everyone! I will be posting some more questions as I have 24 "little" programs that have to be written before I can take my mid term..... Heavy heavy math. Highschool was um.... too many years ago to remember and I only took Algebra II in college. I might be in trouble. Trying to understand what that squiggly "E" means....
You guys have all been a great help! Thanks so much! Stephanie --- In [email protected], "Nico Heinze" <[EMAIL PROTECTED]> wrote: > > --- In [email protected], Thomas Hruska <thruska@> wrote: > > > > onecrazeemom wrote: > > > I finally completed the dice roll program. Now, what do > > > I do to make the rolls more random? They seem to come up > > > with doubles quite often. > > > I used srand( time(0)) to get my random numbers. > > > I used the modulus(I > > > think that is what it is called) > > > > > > dieOne = 1 + rand() %6; > > > dieTwo = 1 + rand() %6; > > > > > > srand( time(0) ); > > > > > > Just curious what gives you a true random number when the lines of > > > code are run so close together. Here are a couple of rolls: > > > > > > 1. 3, 1 > > > 2. 6, 1 > > > 3. 6, 2 > > > 4. 5, 5 > > > 5. 1, 1 > > > 6. 3, 4 > > > 7. 4, 6 > > > > > > I guess they are more random than I thought, but the first > > > two times I ran the program it came up with doubles. > > > > > > Thanks in advance, > > > Stephanie > > > > Probably what you are "experiencing" is the side effect of > > using the modulus of a random number with a number not > > evenly divisible by the maximum range of the random number > > generator. > > > > True random number generators are MUCH harder to create (all > > the implementations of rand() that I've seen are simple > > congruential pseudorandom generators). You get into heavy > > math and/or cryptography VERY quickly if you start rolling > > your own. > <snip> > > Stephanie, > > if you have access to a well-sorted public library, get your hands on > volume 2 of Donald Knuth's "The Art Of Computer Programming"; really > heavy stuff to work through, but he explained the basics of > pseudo-number generation so well that this writing is still valid > (it's been written in the early 1970's). > And he explains how you can test your own pseudo-random number > generators for their quality without much effort, only some time to > have your check program run it. Pretty easy to implement. And very > well explained (though the math background is too heavy for me). > > Regards, > Nico >
