ProgBasicsJavaBook3.1SimpleConditions16Number0to100toText

import java.util.Scanner;

public class Main {

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

        int number = Integer.parseInt(scanner.nextLine());

        if (number >= 0 && number <= 19) {
            switch (number) {
                case 0:
                    System.out.println("zero");
                    break;
                case 1:
                    System.out.println("one");
                    break;
                case 2:
                    System.out.println("two");
                    break;
                case 3:
                    System.out.println("three");
                    break;
                case 4:
                    System.out.println("four");
                    break;
                case 5:
                    System.out.println("five");
                    break;
                case 6:
                    System.out.println("six");
                    break;
                case 7:
                    System.out.println("seven");
                    break;
                case 8:
                    System.out.println("eight");
                    break;
                case 9:
                    System.out.println("nine");
                    break;
                case 10:
                    System.out.println("ten");
                    break;
                case 11:
                    System.out.println("eleven");
                    break;
                case 12:
                    System.out.println("twelve");
                    break;
                case 13:
                    System.out.println("thirteen");
                    break;
                case 14:
                    System.out.println("fourteen");
                    break;
                case 15:
                    System.out.println("fifteen");
                    break;
                case 16:
                    System.out.println("sixteen");
                    break;
                case 17:
                    System.out.println("seventeen");
                    break;
                case 18:
                    System.out.println("eighteen");
                    break;
                case 19:
                    System.out.println("nineteen");
                    break;
            }
        } else if (number >= 20 && number <= 99) {
            int tenths = number / 10;
            int units = number % 10;

            switch (tenths) {
                case 2:
                    System.out.print("twenty");
                    break;
                case 3:
                    System.out.print("thirty");
                    break;
                case 4:
                    System.out.print("fourty");
                    break;
                case 5:
                    System.out.print("fifty");
                    break;
                case 6:
                    System.out.print("sixty");
                    break;
                case 7:
                    System.out.print("seventy");
                    break;
                case 8:
                    System.out.print("eighty");
                    break;
                case 9:
                    System.out.print("ninety");
                    break;
            }

            switch (units) {
                case 1:
                    System.out.print(" one");
                    break;
                case 2:
                    System.out.print(" two");
                    break;
                case 3:
                    System.out.print(" three");
                    break;
                case 4:
                    System.out.print(" four");
                    break;
                case 5:
                    System.out.print(" five");
                    break;
                case 6:
                    System.out.print(" six");
                    break;
                case 7:
                    System.out.print(" seven");
                    break;
                case 8:
                    System.out.print(" eight");
                    break;
                case 9:
                    System.out.print(" nine");
                    break;
            }
        } else if (number == 100) {
            System.out.println("one hundred");
        } else {
            System.out.println("invalid number");
        }

    }
}