pathikrit

val n = 9
val s = Math.sqrt(n).toInt
type Board = IndexedSeq[IndexedSeq[Int]]
 
def solve(board: Board, cell: Int = 0): Option[Board] = (cell%n, cell/n) match {
  case (r, `n`) => Some(board)
  case (r, c) if board(r)(c) > 0 => solve(board, cell + 1)
  case (r, c) =>
    def guess(x: Int) = solve(board.updated(r, board(r).updated(c, x)), cell + 1)  
    val used = board.indices.flatMap(i => Seq(board(r)(i), board(i)(c), board(s*(r/s) + i/s)(s*(c/s) + i%s)))

visenger

#!/bin/sh

# one way (older scala version will be installed)
# sudo apt-get install scala

#2nd way
sudo apt-get remove scala-library scala
wget http://www.scala-lang.org/files/archive/scala-2.11.4.deb
sudo dpkg -i scala-2.11.4.deb
sudo apt-get update