OpenEuphoria

Re: random numbers

• Posted by Jason Gade <jaygade at ?ahoo.co?> Nov 22, 2007
• 563 views

c.k.lester wrote:
> 
> Allen Ashby wrote:
> > 
> > I am trying to generate 52 random numbers 1-52 without duplicating any
> > numbers.
> > it seems every time I try I get duplications. Does anyone have a
> > solution for this.
> 
> Start with a sequence {1..52} and pull them from that.
> 
> s = {1,2,3,4,5,6,7,8,9,...52}
> n = {}
> for t=1 to 52 do
>    r = rand(length(s)) -- grab a random position
>    n &= s[r] -- add it to our new sequence
>    s = s[1..r-1] & s[r+1..$] -- remove from available numbers
> end for

This would have been my solution as well. Nice!

I would only change it slightly:

s = {1,2,3,4,5,6,7,8,9,...52}
n = repeat(0, 52)
for t=1 to 52 do
   r = rand(length(s)) -- grab a random position
   n[t] = s[r] -- add it to our new sequence
   s = s[1..r-1] & s[r+1..$] -- remove from available numbers
end for

--
A complex system that works is invariably found to have evolved from a simple
system that works.
--John Gall's 15th law of Systemantics.

"Premature optimization is the root of all evil in programming."
--C.A.R. Hoare

j.