06_ParallelGraphContraction.scala

package lecture3

import scala.collection._
import scala.collection.parallel.CollectionConverters.MapIsParallelizable

@main def parallelGraphContraction =
  val graph = mutable.Map[Int, Int]() ++= (0 until 100000).map(i => (i, i+1))
  graph(graph.size - 1) = 0
  for((k, v) <- graph.par) graph(k) = graph(v)
  val violation = graph.find {
    case (i, v) => v != (i + 2) % graph.size
  }
  println(s"violation: $violation")