GreedyFlorist.java

import java.io.*;
import java.math.*;
import java.security.*;
import java.text.*;
import java.util.*;
import java.util.concurrent.*;
import java.util.regex.*;

public class Solution {

    static int getMinimumCost(int k, Integer[] c) {
        //O(nlogn) Time, O(n) Space. Order in descending order, then we can calculate min cost.
        Arrays.sort(c, Collections.reverseOrder());

        int result = 0;

        for (int i = 0; i < c.length; i++) {
            result += ((i / k) + 1) * c[i];
        }

        return result;
    }

    private static final Scanner scanner = new Scanner(System.in);

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

        String[] nk = scanner.nextLine().split(" ");

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

        int k = Integer.parseInt(nk[1]);

        Integer[] c = new Integer[n];

        String[] cItems = scanner.nextLine().split(" ");
        scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");

        for (int i = 0; i < n; i++) {
            int cItem = Integer.parseInt(cItems[i]);
            c[i] = cItem;
        }

        int minimumCost = getMinimumCost(k, c);

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

        bufferedWriter.close();

        scanner.close();
    }
}