https://www.hackerrank.com/challenges/luck-balance/problem?h_l=interview&playlist_slugs%5B%5D=interview-preparation-kit&playlist_slugs%5B%5D=greedy-algorithms

Result.java

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 'luckBalance' function below.
     *
     * The function is expected to return an INTEGER.
     * The function accepts following parameters:
     *  1. INTEGER k
     *  2. 2D_INTEGER_ARRAY contests
     */

    public static int luckBalance(int k, List<List<Integer>> contests) {
        final int nonImportantSum = contests.stream().filter(it -> it.get(1).equals(0)).map(it -> it.get(0)).mapToInt(Integer::intValue).sum();
        List<Integer> importantPairs = contests
                .stream()
                .filter(it -> it.get(1).equals(1))
                .map(it -> it.get(0))
                .collect(Collectors.toList());
        Collections.sort(importantPairs, Collections.reverseOrder());

        final int lostImportantSum = importantPairs.subList(0, Math.min(k, importantPairs.size()))
                .stream()
                .mapToInt(Integer::intValue)
                .sum();
        final int wonImportantSum = importantPairs.subList(Math.min(k, importantPairs.size()), importantPairs.size())
                .stream()
                .mapToInt(Integer::intValue)
                .sum();


        return nonImportantSum + lostImportantSum - wonImportantSum;
    }


}

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 k = Integer.parseInt(firstMultipleInput[1]);

        List<List<Integer>> contests = new ArrayList<>();

        IntStream.range(0, n).forEach(i -> {
            try {
                contests.add(
                    Stream.of(bufferedReader.readLine().replaceAll("\\s+$", "").split(" "))
                        .map(Integer::parseInt)
                        .collect(toList())
                );
            } catch (IOException ex) {
                throw new RuntimeException(ex);
            }
        });

        int result = Result.luckBalance(k, contests);

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

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

20'