02. Easter Party - Solution

import java.util.Scanner;

public class EasterParty {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        int guestsCnt = Integer.parseInt(scanner.nextLine());
        double couvertPrice = Double.parseDouble(scanner.nextLine());
        double budget = Double.parseDouble(scanner.nextLine());

        double discount = 0.0;
        if (guestsCnt >= 10 && guestsCnt <= 15) {
            discount = 0.15;
        } else if (guestsCnt > 15 && guestsCnt <= 20) {
            discount = 0.20;
        } else if (guestsCnt > 20) {
            discount = 0.25;
        }

        double cakePrice = budget * 0.1;
        double couvertSum = guestsCnt * couvertPrice;
        couvertSum -= couvertSum * discount;
        couvertSum += cakePrice;

        if (couvertSum <= budget) {
            System.out.printf("It is party time! %.2f leva left. ", budget - couvertSum);
        } else {
            System.out.printf("No party! %.2f leva needed.", couvertSum - budget);
        }
    }
}