NZEC on hackerearth - Scala - Judge寻找内部阶级的主要方法

Question

我有一个在本地工作的问题的代码，但当我上传到hackerearth时，我得到一个NZEC，代码结构如下：

import scala.annotation.tailrec
object SamuAndCardGame extends App {

  case class Board(w: Long, h: Long) {
    def validPos(v: Vec) = {
      v.x >=1 && v.x <= w && v.y >= 1 && v.y <= h
    }
  }

  case class Vec(x: Long, y: Long) {
    def +(other: Vec) = {
      Vec(this.x + other.x, this.y + other.y)
    }
  }

  def validJumps(board: Board, jumps: Seq[Vec]) = {
    @tailrec
    def rec(currPos:Vec, jump:Int, count: Long): Long = {
      if(jump >= jumps.size) count
      else{
        val newPos = currPos + jumps(jump)
        if(board.validPos(newPos)) rec(newPos, jump , count + 1)
        else rec(currPos, jump + 1, count)
      }
    }

    rec(Vec(1,1), 0, 0)
  }

  val in = io.Source.stdin.getLines()
  val tc = in.next.toInt
  for(_ <- 1 to tc){
    val Array(n, m)= in.next.split(" ").map(_.toInt)
    val board = Board(m,n)
    val k = in.next.toInt
    var count = 0
    val jumps = for(_ <- (1 to k)) yield {
      val line =  in.next
      val Array(a, b) = line.split(" ").map(_.toLong)
       Vec(a, b)
    }
    println(validJumps(board, jumps))
  }
}

hackerearth关于运行时错误的输出如下：

java.lang.NoSuchMethodException: SamuAndCardGame$Vec.main([Ljava.lang.String;)
    at java.lang.Class.getMethod(Class.java:1786)
    at scala.reflect.internal.util.ScalaClassLoader$class.run(ScalaClassLoader.scala:66)
    at scala.reflect.internal.util.ScalaClassLoader$URLClassLoader.run(ScalaClassLoader.scala:101)
    at scala.tools.nsc.CommonRunner$class.run(ObjectRunner.scala:22)
    at scala.tools.nsc.ObjectRunner$.run(ObjectRunner.scala:39)
    at scala.tools.nsc.CommonRunner$class.runAndCatch(ObjectRunner.scala:29)
    at scala.tools.nsc.ObjectRunner$.runAndCatch(ObjectRunner.scala:39)
    at scala.tools.nsc.MainGenericRunner.runTarget$1(MainGenericRunner.scala:65)
    at scala.tools.nsc.MainGenericRunner.run$1(MainGenericRunner.scala:87)
    at scala.tools.nsc.MainGenericRunner.process(MainGenericRunner.scala:98)
    at scala.tools.nsc.MainGenericRunner$.main(MainGenericRunner.scala:103)
    at scala.tools.nsc.MainGenericRunner.main(MainGenericRunner.scala)

我不明白为什么Hackerearth试图在内部类Vec而不是外部对象SamuAndCardGame上找到主要方法。

如果遇到类似问题的人会给我一些指导，我将不胜感激。