compute fibonacci number / published by https://github.com/dacr/code-examples-manager #0e363d0a-3312-480c-8ceb-69c547dce4a6/984f9b16dcf2e54b0b5a305896703a678feabc04

math-fibonacci.sc

// summary : compute fibonacci number
// keywords : scala, math, fibonacci, @testable
// publish : gist
// authors : David Crosson
// license : Apache License Version 2.0 (https://www.apache.org/licenses/LICENSE-2.0.txt)
// id : 0e363d0a-3312-480c-8ceb-69c547dce4a6
// created-on : 2021-04-06T10:48:09Z
// managed-by : https://github.com/dacr/code-examples-manager
// run-with : scala-cli $file

// ---------------------
//> using scala "3.4.2"
//> using dep "org.scalatest::scalatest:3.2.16"
//> using objectWrapper
// ---------------------
import org.scalatest._
import flatspec._
import matchers._

// TODO - to be improved
def fib(n:BigInt):BigInt = {
  if (n<=0) 0
  else if (n ==1) 1
  else fib(n-1)+fib(n-2)
}

class FactTest extends AnyFlatSpec with should.Matchers {
  override def suiteName: String = "FactTest"

  "fibonacci" should "return the right result" in {
    fib(0) shouldBe 0
    fib(1) shouldBe 1
    fib(2) shouldBe 1
    fib(3) shouldBe 2
    fib(4) shouldBe 3
    fib(16) shouldBe 987
    fib(20) shouldBe 6765
    fib(30) shouldBe 832040
    fib(40) shouldBe 102334155
    //fib(49) shouldBe BigInt("7778742049")
    //fib(50) shouldBe BigInt("12586269025")
    //fib(100) shouldBe BigInt("354224848179261915075")
    //fib(200) shouldBe BigInt("280571172992510140037611932413038677189525")
    //fib(300) shouldBe BigInt("222232244629420445529739893461909967206666939096499764990979600")
  }
}

org.scalatest.tools.Runner.main(Array("-oDF", "-s", classOf[FactTest].getName))