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 JavaScript (node.js v5.12) (judge verdict: Wrong Answer)

'use strict'

const Main = input => {
  const row_list = input.split('\n');
  const row0_sp = row_list[0].split(' ');
  const items = row_list[1].split(' ').map(item => Number(item));
  const N = row0_sp[0]; const M = row0_sp[1];
  
  items.sort((a,b)=>b-a);

  let sum = 0;
  for(let item of items) sum += item;

  const border = sum * (1 / (4 * M + 1));

  let canSelect = true;

  for(let i=0; i<M; i++) {
    if(items[i] < border) {
      canSelect = false;
      break;
    }
  }

  console.log(canSelect ? 'Yes' : 'No');
}

//Main(require('fs').readFileSync('/dev/stdin', 'utf8'));
Main(`3 2
380 19 1`);