Brute Force nQueens

nQueens.scala

object nQueens extends App {
  type Solution = IndexedSeq[Int]

  def createSolutions(n: Int): Seq[Solution] = {
    (0 until n).permutations.toSeq
  } 

  def verifySolution(s: Solution): Boolean = {
    s.indices.combinations(2).forall(x => Math.abs(x(0) - x(1)) != Math.abs(s(x(0)) - s(x(1))))
  }

  def nQueens(n: Int): Seq[Solution] = {
    (0 until n).permutations
        .filterNot(s => s.indices
                         .combinations(2)
                         .exists(c => Math.abs(c(0) - c(1)) == Math.abs(s(c(0)) - s(c(1)))))
        .toSeq
  }

  println(nQueens(8))
}