Question

Im trying to generate n unique random numbers between 1 and max

I tried the following code but doesn’t work (returns repeated numbers)

r = [ ]
n.times { v = rand(max) while r.include? v ; r << v}

Whats wrong with it? Thanks

added:

max is thousands

n is 10

Answer 1

I think your while r.include logic is the wrong way around. Try this:

r = [ ]
while r.length < n 
  v = rand(max)
  r << v unless r.include? v
end

Note that this will go into an infinite loop if max < n.