Main.scala

package me.masahito

import scala.annotation.tailrec

object Main {
  def getConsecutiveIndexes[T](t: (List[T], List[T])): List[Int] = {
    pullConsecutiveNumbers(getSameElementsIndexList(t))
  }
  
  def getSameElementsIndexList[T] (t: (List[T], List[T])): List[Int] = {
    {0 to (t._1.zip(t._2).size -1)}.filter(i => t._1(i) == t._2(i)).toList
  }

  @tailrec
  private def pullConsecutiveNumbersRecursive(list: List[Int], last:Int ,acc:List[Int]) : List[Int] = {
    if(list.head - last == 1) pullConsecutiveNumbersRecursive(list.tail, list.head, list.head :: acc)
    else acc.reverse
  }

  def pullConsecutiveNumbers(list:List[Int]): List[Int] = {
    pullConsecutiveNumbersRecursive(list.tail, list.head, List(list.head) )
  }

MainTest.scala

package me.masahito

import org.scalatest.FunSuite

/**
 * Created by masahito on 2014/08/22.
 */
class MainTest extends FunSuite {
  test("get match index list") {
    val a = (List(1,2,3,4,5), List(1,2,3,5,5))
    assert(Main.getSameElementsIndexList(a) === List(0,1,2,4))
  }

  test("empty list") {
    val a = (List.empty[Int], List.empty[Int])
    assert(Main.getSameElementsIndexList(a) === List.empty[Int])
  }

  test("pullConsecutiveNumbers") {
    val a = List(1,2,3,4,6)
    assert(Main.pullConsecutiveNumbers(a) === List(1,2,3,4))
  }
  test("lsit match + pullConsecutiveNumbers") {
    val a = (List(1,2,3,4,5), List(1,2,3,5,5))
    assert(Main.pullConsecutiveNumbers(Main.getSameElementsIndexList(a)) === List(0,1,2))
  }
}