lnds

if i >= tam {
	return nil
} else if c < "0" || c > "9" {
	return nil
} else {
 ...
}

lnds

if !c.is_digit(10) { return Error } 
else if i >= tam   { return Error } 
else { ... }

lnds

def validar(tam:Int, accion:String) : Option[Array[Int]] = 
  if (accion.exists(!_.isDigit))
  	None
  else {
  	val num = accion.map(_.toInt - '0'.toInt).distinct
  	if (num.length == tam && num.length == accion.length)
  		Some(num.toArray)	
  	else 
  		None	
  }

lnds

def validar(tam:Int, accion:String) : Option[Array[Int]] = 
  if (accion.exists(c => !c.isDigit) None
  else {
    val num = accion.map(c => c.toInt - '0'.toInt).distinct
    if (num.length == tam && num.length == accion.length)
      Some(num.toArray)
    else
      None
  }

lnds

let validar tam accion =
    let cars = [for c in accion -> c]
    if List.exists (fun c -> not (Char.IsDigit c)) cars then List.empty<int>
    else 
        let org = List.map (fun c -> (int c) - (int '0')) cars
        let num = List.distinct org
        if (List.length org <> List.length num) || (List.length num <> tam) then List.empty<int>
        else num

lnds

if (!it.value.isDigit())
    return null
if (it.index >= tam)
    return null
else {
    val digit = it.value.toInt() - '0'.toInt()
    if (digit in num) return null
    num = num.plus(digit)
}

lnds

validar n xs   
  | length num /= n = []
  | otherwise = num
   where num = if not (all isDigit xs) then [] else remover_dups xs

lnds

(defn validar [tam num]
  (if (and  (solo-digitos num) (largo-esperado tam num))    
    (map #(Character/digit % 10) (seq num))
    nil))

lnds

(defn validar [tam num]
  (if (and  (every? #(Character/isDigit %) num)) 
      (let [cuenta-unicos (count (distinct num))]
        (and 
          (= tam cuenta-unicos)
          (= (count num) cuenta-unicos)))))    
    (map #(Character/digit % 10) (seq num))
    nil))

lnds

Digitos = lists:all(fun (X) -> is_digit(X) end, Entrada), 
	if Digitos =:= true -> unicos(to_num(Entrada), Tam, Len) ; 
	   Digitos =:= false -> [] end.