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 Java7 (OpenJDK 1.7.0) (judge verdict: Accepted)

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.lang.reflect.Array;
import java.util.StringTokenizer;
import java.util.Scanner;
import java.lang.*;
import java.io.*;
import java.util.*;
import java.lang.Integer;
import java.util.HashMap;

public class Main {
    // driver function to test the above functions
    public static void main(String args[]) throws IOException {
        Reader.init(System.in);
        int n = Reader.nextInt();
        int m = Reader.nextInt();
        int[] arr = new int[n];

        double sum  = 0;
        for (int i=0; i<n; i++){
            arr[i] = Reader.nextInt();
            sum = sum+arr[i];
        }
        sum = (double)(sum/(4*m));
        int ans=0;
        for (int i=0; i<n; i++){
            int val = arr[i];
            if (val>=sum){
                ans++;
            }
        }
        if (ans>=m) {
            System.out.println("Yes");
        }
        else {
            System.out.println("No");
        }

    }
}

class Node{
    char val;
    Node nxt = null;
    Node prev=null;


}



class solu{

}

/** Class for buffered reading int and double values */
class Reader {
    static BufferedReader reader;
    static StringTokenizer tokenizer;

    /** call this method to initialize reader for InputStream */
    static void init(InputStream input) {
        reader = new BufferedReader(
                new InputStreamReader(input) );
        tokenizer = new StringTokenizer("");
    }

    /** get next word */
    static String next() throws IOException {
        while ( ! tokenizer.hasMoreTokens() ) {
            //TODO add check for eof if necessary
            tokenizer = new StringTokenizer(
                    reader.readLine() );
        }
        return tokenizer.nextToken();
    }

    static int nextInt() throws IOException {
        return Integer.parseInt( next() );
    }

    static long nextLong() throws IOException {
        return Long.parseLong( next() );
    }

    static double nextDouble() throws IOException {
        return Double.parseDouble( next() );
    }

    static String line() throws IOException {
        return reader.readLine();
    }
}