My point was simply that if you want me to select a random number, but hands me of list of numbers I'm not allowed to pick, it can't really be random. If you limit the length of the number (this is programming - there is always a limit) there is a maximum of how many "random" numbers I can give you ;-)
On Wed, Jun 19, 2013 at 2:25 PM, Kristopher Micinski <[email protected]> wrote: > That's not true, it can still be random: just over a different state > space. (In particular [0-9]^n \ {alpha^n | any character is repeated > in alpha}) > > OP: you could pull out a statistics book and read about random events, > how to generate them using coins, etc... But the easiest way is to > generate a random number, add it to the list if it's not already in > the list, etc... The uniformity argument works based on the invariant > that at each stage the next number you choose to "fix" the rest of > your choices is random, hence the distribution remains random. > > # let assemble_random_nums len = > let rand () = (Random.int 9) + 1 in > let rec h l = function > | 0 -> l > | i -> let r = rand () in if (List.mem r l) then (h l i) else (h > (r::l) (i-1)) > in > h [] len;; > val assemble_random_nums : int -> int list = <fun> > # assemble_random_nums 4;; > - : int list = [1; 8; 3; 9] > # assemble_random_nums 4;; > - : int list = [2; 9; 5; 4] > # assemble_random_nums 4;; > > Kris > > On Wed, Jun 19, 2013 at 7:03 AM, Michael Banzon <[email protected]> wrote: >> First: This isn't really a question related to Android development. >> >> Second: Random unique numbers between 1 and 9 (including both >> extremes) is a set of 9 numbers (I really hope that we are talking >> about integers and not real/floating point numbers). >> >> Third: If you request a unique sequence of numbers 1 to 9 it can't be >> random as it would include a check for uniqueness that would remove >> some degree of randomness. >> >> On Wed, Jun 19, 2013 at 11:56 AM, vamshi ch <[email protected]> wrote: >>> Hi All, >>> >>> In my application i want to generate random numbers between 1 to 9 and >>> that is unique. once i get the random number that should not be repeated for >>> any one, any where and for me also. it's similar to OTP(one time password) >>> but some time OTP will be repeated and that is alphanumerical but in my case >>> that should not be happen and i need numbers only. >>> >>> Please can you tell me what is the approach to achieve it. Please help out >>> of this.. >>> >>> >>> Please share the code if you have any regarding this.. >>> >>> -- >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "Android Developers" group. >>> To post to this group, send email to [email protected] >>> To unsubscribe from this group, send email to >>> [email protected] >>> For more options, visit this group at >>> http://groups.google.com/group/android-developers?hl=en >>> --- >>> You received this message because you are subscribed to the Google Groups >>> "Android Developers" group. >>> To unsubscribe from this group and stop receiving emails from it, send an >>> email to [email protected]. >>> For more options, visit https://groups.google.com/groups/opt_out. >>> >>> >> >> >> >> -- >> Michael Banzon >> http://michaelbanzon.com/ >> >> -- >> -- >> You received this message because you are subscribed to the Google >> Groups "Android Developers" group. >> To post to this group, send email to [email protected] >> To unsubscribe from this group, send email to >> [email protected] >> For more options, visit this group at >> http://groups.google.com/group/android-developers?hl=en >> --- >> You received this message because you are subscribed to the Google Groups >> "Android Developers" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> For more options, visit https://groups.google.com/groups/opt_out. >> >> > > -- > -- > You received this message because you are subscribed to the Google > Groups "Android Developers" group. > To post to this group, send email to [email protected] > To unsubscribe from this group, send email to > [email protected] > For more options, visit this group at > http://groups.google.com/group/android-developers?hl=en > --- > You received this message because you are subscribed to the Google Groups > "Android Developers" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/groups/opt_out. > > -- Michael Banzon http://michaelbanzon.com/ -- -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-developers?hl=en --- You received this message because you are subscribed to the Google Groups "Android Developers" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
