Marc's_Cakewalk.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 'marcsCakewalk' function below.
     *
     * The function is expected to return a LONG_INTEGER.
     * The function accepts INTEGER_ARRAY calorie as parameter.
     */

    public static long marcsCakewalk(List<Integer> calorie) 
    {
       // Write your code here
       
       //after looking the above test cases...(first sort the list in descending order..)
       Collections.sort(calorie);  //sort in ascending order..
       Collections.reverse(calorie);  //this will reverse the list in descending order..
       
       //now traverse the list..
       int i;
       long sum=0;
       for(i=0;i<calorie.size();i++)
       {
           long p = (long)Math.pow(2,i);
           long mul = p*calorie.get(i);
           sum = sum+mul;
       }
       return sum;
    }
}
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")));

        int n = Integer.parseInt(bufferedReader.readLine().trim());

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

        long result = Result.marcsCakewalk(calorie);

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

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