rcongiu

  def pairGifts(l:Seq[Person]) = {
    @tailrec
    def innerPair(pairs:Seq[(Person,Person)], b:List[Person], r:List[Person]):Seq[(Person,Person)] = {
      // avoid last giving to itself
      if(b.size == 2 && b.last == r.last) return pairs :+ (b.head, r.last) :+ (b.last, r.head)
      (b, r) match {
        case (Nil, Nil) =>  pairs
        case ( (bh :: bt), (rh :: rt))  =>
        // avoid one person give to himself. In that case, pick next and put back current
          val (recipient, recipients)  = if (bh != rh) (rh, rt) else ( rt.head, rh :: rt.tail)

rcongiu

Keybase proof

I hereby claim:

• I am rcongiu on github.
• I am drcongiu (https://keybase.io/drcongiu) on keybase.
• I have a public key ASC1zbptwtMmXIkqD-MG16Vj8Sfl982JyFTzZAE7_9eDiwo

To claim this, I am signing this object: