Scala堆栈溢出错误

Question

我是 Scala 新手，在处理这部分代码时遇到了问题。我在第 18 / 20 行遇到堆栈溢出错误，但我不知道为什么。

def quicksort(list : List[Int]) : List[Int] = list match {
  case Nil => List()
  case x::Nil => List(x)
  case x::xs => {
    val lesserList = partitionLesser(list.tail, list(0))
    val greaterList = partitionGreater(list.tail, list(0))
    quicksort(lesserList ::: List(x) ::: greaterList)
  }
}

def partitionLesser(list : List[Int], pivot : Int) : List[Int] = list match{
  case Nil => List()
  case x::Nil => List(x)
  case x::xs => {
    if(x <= pivot) { x :: partitionLesser(list.tail, pivot) }
    else { partitionLesser(list.tail, pivot) } 
  }
}

def partitionGreater(list : List[Int], pivot : Int) : List[Int] = list match {
  case Nil => List()
  case x::Nil => List(x)
  case x::xs => {
    if(x > pivot) { x :: partitionGreater(list.tail, pivot) }
    else { partitionLesser(list.tail, pivot)}
  }
}

Answer 1

def quicksort(list : List[Int]) : List[Int] = list match {
  case Nil => List()
  case x::Nil => List(x)
  case x::xs => {
    val lesserList = partitionLesser(list.tail, list(0))
    val greaterList = partitionGreater(list.tail, list(0))
    // quicksort(lesserList ::: List(x) ::: greaterList)
    quicksort(lesserList) ::: List(x) ::: quicksort(greaterList)
  }
}