polynomial.scala

package fr.leboncoin.botdet.job.offline

object Test extends App {

  implicit class IntOps(x: Int) {
    def **(p: Int): Int = (1 to p).foldLeft(1) {
      case (acc, elem) => acc * x
    }
  }

  val coefAndOrder = List((6, 3), (4, 2), (3, 1), (2, 0))
  val expr = coefAndOrder.map {
    case (coef, order) => if (order == 0) s"$coef" else s"${coef}x^$order"
  }.mkString(" + ")
  println(expr)

  def f(x: Int): Int = {
    coefAndOrder.map {
      case (coef, order) => coef * (x ** order)
    }.sum
  }

  def baseN(number: Int, base: Int): List[Int] = {
    var quotient = number
    var res = List[Int]()
    while (quotient > base) {
      res = (quotient % base) :: res
      quotient = quotient / base
    }
    quotient :: res
  }

def baseNRec(number: Int, base: Int): List[Int] = {
  if (number > base) {
    baseNRec(number / base, base) :+ number % base
  } else {
    List(number)
  }
}

  def resolve(poly: Int => Int): List[Int] = {
    baseNRec(poly(poly(1) + 1), poly(1) + 1)
  }

  println(resolve(f))

}