scala binary search twoliner
```scala []
class Solution(_n: Int, _blacklist: Array[Int]) {
  import scala.util.chaining._
  val inc = _blacklist.sorted.zipWithIndex.map{case (x,i) => (x-i)*2}
  def pick() = util.Random.between(0, _n - _blacklist.length)
    .pipe {i => i+inc.search(i*2+1).insertionPoint}
}
```
['Scala']