这是我对 Scala 的尝试:
case class IndexValue(twosIndex: Int, fivesIndex: Int)
case class OutputValues(twos: Int, fives: Int, value: Int) {
def test(): Boolean = {
Math.pow(2, twos) * Math.pow(5, fives) == value
}
}
def run(last: IndexValue = IndexValue(0, 0), list: List[OutputValues] = List(OutputValues(0, 0, 1))): List[OutputValues] = {
if (list.size > 20) {
return list
}
val twosValue = list(last.twosIndex).value * 2
val fivesValue = list(last.fivesIndex).value * 5
if (twosValue == fivesValue) {
val lastIndex = IndexValue(last.twosIndex + 1, last.fivesIndex + 1)
val outputValues = OutputValues(value = twosValue, twos = list(last.twosIndex).twos + 1, fives = list(last.fivesIndex).fives + 1)
run(lastIndex, list :+ outputValues)
} else if (twosValue < fivesValue) {
val lastIndex = IndexValue(last.twosIndex + 1, last.fivesIndex)
val outputValues = OutputValues(value = twosValue, twos = list(last.twosIndex).twos + 1, fives = list(last.twosIndex).fives)
run(lastIndex, list :+ outputValues)
} else {
val lastIndex = IndexValue(last.twosIndex, last.fivesIndex + 1)
val outputValues = OutputValues(value = fivesValue, twos = list(last.fivesIndex).twos, fives = list(last.fivesIndex).fives + 1)
run(lastIndex, list :+ outputValues)
}
}
val initialIndex = IndexValue(0, 0)
run(initialIndex, List(OutputValues(0, 0, 1))) foreach println
输出:
OutputValues(0,0,1)
OutputValues(1,0,2)
OutputValues(2,0,4)
OutputValues(0,1,5)
OutputValues(3,0,8)
OutputValues(1,1,10)
OutputValues(4,0,16)
OutputValues(2,1,20)
OutputValues(0,2,25)
OutputValues(5,0,32)
OutputValues(3,1,40)
OutputValues(1,2,50)
OutputValues(6,0,64)
OutputValues(4,1,80)
OutputValues(2,2,100)
OutputValues(0,3,125)
OutputValues(7,0,128)
OutputValues(5,1,160)
OutputValues(3,2,200)
OutputValues(1,3,250)
OutputValues(8,0,256)