Daenyth

package teikametrics

import scala.collection.SortedMap

/**
  * Immutable implementation of an LRU cache.
  *
  * @author Twitter
  *
  *  Copy pasted from the version previously in twitter-util v19.1.0 at

danilbykov

import cats.effect.ExitCase._
import cats.effect.Sync
import cats.effect.concurrent.Ref
import cats.syntax.flatMap._
import cats.syntax.functor._

trait Tap[F[_]] {
  def apply[A](effect: F[A]): F[A]
}

pathikrit

Libraries

• Web Server: Play (framework) or http4s (library)
• Actors: akka
• Asynchronous Programming: monix (for tasks, reactors, observables, scheduler etc)
• Authentication: Silhouette
• Authorization: Deadbolt
• Command-line option parsing: case-app
• CSV Parsing: kantan.csv
• DB: doobie (for PostgreSQL)

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)))