package main

/**
  * Created by claudio on 27/11/16.
  */
object Main {
  def main(args: Array[String]): Unit = {
    val fruits = List("apples", "pears", "bananas")
    val fruitsAndLemon = "lemon" :: fruits
    val one :: two :: rest = fruitsAndLemon
    println(s"$one $two $rest")

    val nums = 3 :: 2 :: 1 :: Nil
    println(isort(nums))
    println(msort[Int](_ < _)(nums))
    println(concatenate(1 :: 2 :: 3 :: Nil, 4 :: 5 :: Nil))
  }
  def isort(list: List[Int]): List[Int] = list match {
    case Nil => Nil
    case head :: tail => insert(head, isort(tail))
  }
  def insert(head: Int, tail: List[Int]): List[Int] = tail match {
    case Nil => head :: Nil
    case tailHead :: tailTail =>
      if(head < tailHead) head :: tail
      else tailHead :: insert(head, tailTail)
  }
  def concatenate[T](first: List[T], second: List[T]): List[T] = first match {
    case Nil => second
    case firstHead :: firstTail => firstHead :: concatenate(firstTail, second)
  }
  def msort[T](less: (T,T) => Boolean)(list: List[T]): List[T] = list match{
    case Nil => Nil
    case a :: Nil => a :: Nil
    case _ =>
      val length = list.length/2
      val front = msort(less)(list take length)
      val ending = msort(less)(list drop length)
      if(less(front.head,ending.head)) front ::: ending
      else ending ::: front
  }
}