scala递归实现换零钱算法

 import scala.collection.mutable.ArrayBuffer
 import scala.util.control.Breaks

 object Exchange {
   def delete(arg:ArrayBuffer[Int]):ArrayBuffer[Int]={
     val breakables = new Breaks
     breakables.breakable {
       for (i <- 0 until arg.length) {
         if (arg(i) == arg.max) {
           arg.remove(i)
           breakables.break()
         }
       }
     }
     arg
   }
   def exchange(total:Int,money:ArrayBuffer[Int]):Int={
     if (total==0)
       1
     else if(total<0||money.length==0)
       0
     else{
       //var newMoney=money这种赋值方式，newMoney其实不是一个新的数组
       val newMoney = for(elem <- money) yield elem
       delete(newMoney)
       exchange((total-money.max),money)+exchange(total,newMoney)
     }
   }
   def main(args:Array[String]): Unit ={
     val ab = ArrayBuffer[Int](50,20,10,5,2,1)
     println(exchange(100,ab))
   }
 }