scala实战学习-快速排序

def qSort(a:List[Int]):List[Int]={

    if(a.length < 2)

        a

    else

        qSort(a.filter(a.head > _)) ++

        a.filter(a.head == _) ++

        qSort(a.filter(a.head < _))

}

qSort(List(9,3,2,6,3,7,8,3,6,9,21))