Project Euler: Probrem 2

euler0002.py

def fibo_iter(n):
  l = []
  x, y = 1, 1
  while y < n:
    l.append(y)
    x, y = y, x+y
  return l

def fibo_rec(x,y,n,l):
  l.append(x)
  return l if y>n else fibo_rec(y,x+y,n,l)

print sum([a for a in fibo_iter(4*10**6) if a%2==0])
print sum([a for a in fibo_rec(1,2,4*10**6,[]) if a%2==0])

Euler0002.scala

object Euler0002 {

  def main(args: Array[String]): Unit =
    println(fibo_rec(1,2,4000000).filter(_%2==0).sum)

  def fibo_rec(x: Int, y: Int, max: Int): List[Int] =
    if (y > max) Nil else y :: fibo_rec(y, x+y, max)
}