public class Calculation {

String productList = "Добавленные товары:";

int numberPersons;

double totalPrice;

Calculation(int numberPersons) {

this.numberPersons = numberPersons;

}

public void addProduct(String product, double price) {

productList = String.format("%s\n%s стоимость: %.2f %s", productList, product, price, getEnding(price));

totalPrice = totalPrice + price;

}

public String divideCheck() {

if (numberPersons == 0) {

return "Ошибка: нет персон";

}

double result = totalPrice / numberPersons;

return String.format("С одного человека: %.2f %s", result, getEnding(result));

}

public String getEnding(double number){

int lastNumber = (int) Math.floor(number);

if (lastNumber > 100) {

lastNumber = lastNumber % 100;

}

if (lastNumber > 20) {

lastNumber = lastNumber % 10;

}

String ending;

switch (lastNumber) {

case 1:

ending = "рубль";

break;

case 2:

case 3:

case 4:

ending = "рубля";

break;

default:

ending = "рублей";

break;

}

return ending;

}

}