scala递归实现换零钱算法 

 1 import scala.collection.mutable.ArrayBuffer
 2 import scala.util.control.Breaks
 3 
 4 object Exchange {
 5   def delete(arg:ArrayBuffer[Int]):ArrayBuffer[Int]={
 6     val breakables = new Breaks
 7     breakables.breakable {
 8       for (i <- 0 until arg.length) {
 9         if (arg(i) == arg.max) {
10           arg.remove(i)
11           breakables.break()
12         }
13       }
14     }
15     arg
16   }
17   def exchange(total:Int,money:ArrayBuffer[Int]):Int={
18     if (total==0)
19       1
20     else if(total<0||money.length==0)
21       0
22     else{
23       //var newMoney=money这种赋值方式，newMoney其实不是一个新的数组
24       val newMoney = for(elem <- money) yield elem
25       delete(newMoney)
26       exchange((total-money.max),money)+exchange(total,newMoney)
27     }
28   }
29   def main(args:Array[String]): Unit ={
30     val ab = ArrayBuffer[Int](50,20,10,5,2,1)
31     println(exchange(100,ab))
32   }
33 }

 

posted @ 2017-11-17 16:17  yuanninesuns  阅读(362)  评论(0)    收藏  举报