Problem:
Score : 200 points

Problem Statement

We have held a popularity poll for N items on sale. Item i received A_i votes.

From these N items, we will select M as popular items. However, we cannot select an item with less than \dfrac{1}{4M} of the total number of votes.

If M popular items can be selected, print Yes; otherwise, print No.

Constraints

1 \leq M \leq N \leq 100

1 \leq A_i \leq 1000

A_i are distinct.

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N M
A_1 ... A_N

Output

If M popular items can be selected, print Yes; otherwise, print No.

Sample Input 1

4 1
5 4 2 1

Sample Output 1

Yes

There were 12 votes in total. The most popular item received 5 votes, and we can select it.

Sample Input 2

3 2
380 19 1

Sample Output 2

No

There were 400 votes in total. The second and third most popular items received less than \dfrac{1}{4\times 2} of the total number of votes, so we cannot select them. Thus, we cannot select two popular items.

Sample Input 3

12 3
4 56 78 901 2 345 67 890 123 45 6 789

Sample Output 3

Yes

Solution in Scala (2.11.7) (judge verdict: Accepted)

import scala.util.control.Breaks

object Main extends App {
  val nm =  scala.io.StdIn.readLine()
  val nmArray = nm.split(" ").map(_.toInt).toSeq
  val n = nmArray(0)
  val m = nmArray(1)

  val aInput =  scala.io.StdIn.readLine()
  val aArray = aInput.split(" ").map(_.toInt).toVector.sorted.reverse
  val aSum = aArray.sum.toDouble
  var result = true

  val b = new Breaks
  b.breakable {
    (1 to m).foreach { i =>
      val target = aArray(i  - 1).toDouble
      val judge = aSum / (4 * m).toDouble
      if(target < judge) {
        result = false
        b.break()
      }
    }
  }
  println(if (result) "Yes" else "No")
}