统计给定Array[Int]数组中正数, 负数, 0所占的比, 依次(正数, 然后负数,然后0)打印结果,使用小数表示即可

PlusMinus.scala

object Solution {

    def main(args: Array[String]) {
        val sc = new java.util.Scanner (System.in);
        var n = sc.nextInt();
        var arr = new Array[Int](n);
        for(arr_i <- 0 to n-1) {
           arr(arr_i) = sc.nextInt();
        }
        
      List(arr.count(_>0)/n.toDouble,arr.count(_<0)/n.toDouble,arr.count(_==0)/n.toDouble).foreach(println)
      
      List((a: Int) => a > 0, (a: Int) => a < 0, (a: Int) => a == 0).map(arr.count(_) / n.toDouble) foreach println
      
       arr.groupBy(math.signum).mapValues(_.length * 1.0 / arr.length)
        .toList.sortWith { case ((_, 0), b) => false case (a, b) => a._2 > b._2 }
        .foreach { case (_, b) => println(b) }

    }
}