斐波那契

a的n次方就是n个a相乘

起始条件：f(a，0) = 1

递归规则：f(a，n) =a*f(a,n-1)(当n≥1时)。求它的第n项

object hai23 {
  def f(n: Int): Int = {
    if (n == 1) {
      1
    } else  if(n ==2){
      2

    }else{
      f(n - 1) +f(n - 2)
    }
  }

  def main(args: Array[String]): Unit = {
    val rst = f(5)
    println(rst)
  }
}

object hai24 {
  def f(a:Int, n: Int): Int = {
    if (n == 0) {
      1
    } else{
      a*f(a,n-1)
    }
  }

  def main(args: Array[String]): Unit = {
    val rst = f(2,3)
    println(rst)
  }
}