Medians

import java.io.*;
import java.math.*;
import java.security.*;
import java.text.*;
import java.util.*;
import java.util.concurrent.*;
import java.util.function.*;
import java.util.regex.*;
import java.util.stream.*;
import static java.util.stream.Collectors.joining;
import static java.util.stream.Collectors.toList;

class Result {

    /*
     * Complete the 'activityNotifications' function below.
     *
     * The function is expected to return an INTEGER.
     * The function accepts following parameters:
     *  1. INTEGER_ARRAY expenditure
     *  2. INTEGER d
     */

    public static int activityNotifications(List<Integer> expenditure, int d) {
    // Write your code here
    int result = 0;
    double median;
    int remove = 0;
    /*
    *create 2 PriorityQueue
    *minHeap contains smaller half of numbers
    *maxHeap contains larger half of numbers
    *populate them with the first d elements of expenditure
    */
    Queue<Integer> minHeap, maxHeap;

    minHeap = new PriorityQueue<>();
    maxHeap = new PriorityQueue<>(Comparator.reverseOrder());

    for (int i = 0; i < d; i++) {
       if (minHeap.size() == maxHeap.size()) {
            maxHeap.offer(expenditure.get(i));
            minHeap.offer(maxHeap.poll());
        } else {
            minHeap.offer(expenditure.get(i));
            maxHeap.offer(minHeap.poll());
        }
    }


    for (int i = d; i < expenditure.size(); i++){
        /*
        *find the median by either:
        *getting the largest element of minHeap
        *Or
        *finding the sum of largest of minHeap and smallest of maxHeap and divide by 2
        */
        if (minHeap.size() > maxHeap.size()) {
            median = minHeap.poll();
        } else {
            median = ((double) minHeap.poll() + maxHeap.poll()) / 2;
        }

        if (expenditure.get(i) >= median * 2) result++;

        /*
        *remove the "first" element from the relevant Queue
        */
        if (!minHeap.remove(expenditure.get(remove))) {
            maxHeap.remove(expenditure.get(remove));
        }

        remove++;

        /*
        *add the next element to the relevant Queue
        */
        if (minHeap.size() == maxHeap.size()) {
            maxHeap.offer(expenditure.get(i));
            minHeap.offer(maxHeap.poll());
        } else {
            minHeap.offer(expenditure.get(i));
            maxHeap.offer(minHeap.poll());
        }
    }

    return result;

    }

}

public class Solution {
    public static void main(String[] args) throws IOException {
        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(System.getenv("OUTPUT_PATH")));

        String[] firstMultipleInput = bufferedReader.readLine().replaceAll("\\s+$", "").split(" ");

        int n = Integer.parseInt(firstMultipleInput[0]);

        int d = Integer.parseInt(firstMultipleInput[1]);

        List<Integer> expenditure = Stream.of(bufferedReader.readLine().replaceAll("\\s+$", "").split(" "))
            .map(Integer::parseInt)
            .collect(toList());

        int result = Result.activityNotifications(expenditure, d);

        bufferedWriter.write(String.valueOf(result));
        bufferedWriter.newLine();

        bufferedReader.close();
        bufferedWriter.close();
    }
}