I worked through the Flowers challenge on hackerrank.com and would like to get feedback on solution and algorithm implementation. It was suggested by hackerrank to review greedy algorithm to solve this challenge. As far as i understand this is an implementation of greedy algorithm

You and your K−1 friends want to buy N flowers. Flower number i has cost ci. Unfortunately the seller does not want just one customer to buy a lot of flowers, so he tries to change the price of flowers for customers who have already bought some flowers. More precisely, if a customer has already bought x flowers, he should pay (x+1)∗ci dollars to buy flower number i.

You and your K−1 friends want to buy all N flowers in such a way that you spend the least amount of money. You can buy the flowers in any order.

Input:

The first line of input contains two integers N and K (K≤N). The next line contains N space separated positive integers c1,c2,…,cN.

Output:

Print the minimum amount of money you (and your friends) have to pay in order to buy all N flowers.

import java.io.*;
import java.util.*;

public class Flowers {

    public static void main(String[] args) {
        /* Enter your code here. Read input from STDIN. Print output to STDOUT. Your class should be named Solution. */
        Scanner sc = new Scanner(System.in);
        ArrayList <Integer> flowerPriceList = new ArrayList<Integer>();
        int numFlowers = sc.nextInt();
        int numFriends = sc.nextInt();
        for(int i = 0; i<numFlowers;i++){
            flowerPriceList.add(sc.nextInt());
        }
        // Sort the ArrayList in reverse order to start bying flowers from most expensive
        Collections.sort(flowerPriceList,Collections.reverseOrder());
        int flowersBought = 0;
        int friendNum = 0;
        int total = 0;
        for(int price:flowerPriceList){
            //itterate throught all the flower prices and calculate the total
            total +=(flowersBought+1)*price;
            friendNum++;
            if(friendNum == numFriends){
                //if all friends bought flowers reset the friend counter and restart the cycle
                friendNum = 0;
                flowersBought++;
            }
        }
        System.out.println(total);
    }
}