[Pendiente]

discrete_non_uniform.hs

-- Basado en
--    https://twitter.com/joseanpg/status/343757288089190401
--    https://twitter.com/joseanpg/status/343758742455738368
--    https://twitter.com/joseanpg/status/343759216424652802
--    Version ultramejorable: http://t.co/da8tx1LK6r
--    Versión Clojure by @jneira:  https://gist.github.com/jneira/5745669 
--                                 con probabilidad inversamente proporcional a las prioridades 


import Random
import Control.Monad

getindex :: [Float] -> Float -> Int
getindex xs v = alpha  xs (sigma * v ) 0
   where sigma = sum xs
         alpha  []     _ i = i
         alpha  (y:ys) a i = let a' = a - y 
                             in if a' < 0 then i
                                else alpha ys a' (i+1)

enjoy gen xs = let zet = getindex xs
               in gen >> randomRIO (0,1) >>= return . zet  >>= print
  	 
main = forever (enjoy newStdGen [20,15,5])

todo_int.hs

-- Si se impone como condición que los pesos sean naturales, no es necesario salir de la artimética Int

import Random
import Control.Monad

getindex :: [Int] -> Int -> Int
getindex xs v = alpha  xs (sigma * v ) 0
   where sigma = sum xs
         alpha  []     _ i = i
         alpha  (y:ys) a i = let a' = a - y 
                             in if a' < 0 then i
                                else alpha ys a' (i+1)

enjoy gen xs = let zet = getindex xs
               in gen >> randomRIO (0,1) >>= return . zet  >>= print
       
main = forever (enjoy newStdGen [20,15,5])