::::::::::::::
Clock.java
::::::::::::::

class Clock {
  public static void main(String[] args) {
    ConsoleReader c = new ConsoleReader(System.in); 
    int h, m; 
    String hour, minu; 
    String line;
    String clock;  
    System.out.print("Where do we start? "); 
    line = c.readLine(); 
    hour = line.substring(0, 2); 
    minu = line.substring(3, 5); 
    h = Integer.parseInt(hour); 
    m = Integer.parseInt(minu); 
    hour = "00" + h; 
    minu = "00" + m; 
    hour = hour.substring(hour.length() - 2); 
    minu = minu.substring(minu.length() - 2); 
    clock = hour + ":" + minu;     
    System.out.print(clock + ">"); 
    line = c.readLine(); 
    while (! line.equals("done")) {
      m = m + 1; 
      if (m >= 60) {
        m = 0; 
        h = h + 1; 
        if (h >= 24) {
          h = 0; 
        } 
      } 
      hour = "00" + h; 
      minu = "00" + m; 
      hour = hour.substring(hour.length() - 2); 
      minu = minu.substring(minu.length() - 2); 
      clock = hour + ":" + minu;     
      System.out.print(clock + ">"); 
      line = c.readLine();
    } 
  } 
}

::::::::::::::
Digits.java
::::::::::::::

class Digits {
    public static void main(String[] args) {
	ConsoleReader c = new ConsoleReader(System.in); 
	String line; 
	int sum, i;  
	System.out.print("Type a number: "); 
        line = c.readLine(); 
	while (! line.equals("done")) {
	    sum = 0; 
	    i = 0; 
            while (i < line.length()) {
		sum = sum + Integer.parseInt(line.substring(i, i+1)); 
                i = i + 1; 
	    }
            System.out.println("The sum of the digits is: " + sum); 
	    System.out.print("Type a number: "); 
	    line = c.readLine();
	}
	System.out.println("Thanks for using this program."); 
    }
}

::::::::::::::
GPA.java
::::::::::::::

class GPA {
    public static void main(String[] args) {
	ConsoleReader c = new ConsoleReader(System.in); 
	System.out.print("Please enter a grade: "); 
	String line; 
	line = c.readLine(); 
	double num; 
	double sum = 0;
	int count = 0; 
	double avg; 
	while (! line.equals("done")) {
	    num = Double.parseDouble(line); 
            if (num >= 0 && num <= 100) { 
		sum = sum + num;
		count = count + 1;
		System.out.println(num + " entered, thank you."); 
	    } else {
		System.out.println(num + " is not a valid score. Disregarded."); 
	    }
	    System.out.print("Please enter a grade: ");
	    line = c.readLine();            
	}
	if (count > 0) {
	    avg = sum / count; 
	    System.out.println(count + " scores, average is " + avg); 
	    if (avg >= 90) {
		System.out.println("Congratulations, the average is above 90."); 
	    } else {
		System.out.println("Average is not above 90, just letting you know."); 
	    }
	} else {
	    System.out.println("No scores, no average."); 
	}

    }
}

::::::::::::::
Investment.java
::::::::::::::

class Investment {
  public static void main(String[] args) {
    ConsoleReader console = new ConsoleReader(System.in); 
    System.out.print("Initial balance: "); 
    double initial, current; 
    int i = 0; 
    initial = console.readDouble(); 
    System.out.print("Interest rate (a number between 0 and 1): "); 
    double rate = console.readDouble(); 
    current = initial; 
    while (current < 2 * initial) {
      current = (1 + rate) * current; 
      i = i + 1; 
      System.out.println(i + ". The balance becomes: " + current + ", the ratio is " + current/initial); 
    } 
  } 
}

::::::::::::::
Menu.java
::::::::::::::

class Menu {
    public static void main(String[] args) {
	ConsoleReader c = new ConsoleReader(System.in); 
	System.out.println("The menu is: 1, 2, 3, 4 (and done to quit): "); 
        String line; 
        System.out.print("Type something: "); 
        line = c.readLine(); 
        while (! line.equals("done")) {
	    if (line.equals("1")) {
		System.out.println("You have typed option " + line); 
	    } else {
		if (line.equals("2")) {
		    System.out.println("You have typed option " + line);
		} else {
		    if (line.equals("3")) {
			System.out.println("You have typed option " + line);
		    } else {
			if (line.equals("4")) {
			    System.out.println("You have typed option " + line);
			} else {
			    System.out.println("Sorry, I don't understand option " + line); 
			}
		    }
		}
	    }
	    System.out.print("Type something: ");
	    line = c.readLine();
	}
    }
}

::::::::::::::
PRS.java
::::::::::::::

class PRS {
  public static void main(String[] args) {
    ConsoleReader console = new ConsoleReader(System.in); 
    int computerScore = 0, userScore = 0; 
    int computer, user;
    String computerWord; 
    String line; 
    computer = (int)(Math.random() * 3); 
    if (computer == 0) { computerWord = "paper"; } 
    else { 
      if (computer == 1) { computerWord = "rock"; } 
      else { 
        if (computer == 2) { computerWord = "scissors"; } 
        else { computerWord = "... ooops, something went wrong!?"; } 
      } 
    } 
    System.out.print("The computer has chosen " + computerWord + ". What do you choose? "); 
    line = console.readLine(); 
    while (! line.equals("done")) {
      if (line.equals("paper")) {
        user = 0; 
      } else {
        if (line.equals("rock")) {
          user = 1; 
        } else {
          if (line.equals("scissors")) {
            user = 2; 
          } else {
            user = -1; // something went wrong. 
          } 
        } 
      } 
      if (user >= 0) {
        if ((user + 1) % 3 == computer) {
          System.out.print("The user has won. "); 
          userScore += 1; 
          System.out.println("The score is now user " + userScore + " - computer " + computerScore); 
        } else { 
          if ((computer + 1) % 3 == user) {
            System.out.print("The computer has won. "); 
            computerScore += 1; 
            System.out.println("The score is now user " + userScore + " - computer " + computerScore); 
          } else {
            System.out.print("This is a tie. "); 
            System.out.println("The score is still " + userScore + " - computer " + computerScore); 
          } 
        } 
      } else {
        System.out.println("Sorry, I don't understand " + line); 
      } 
      computer = (int)(Math.random() * 3); 
      if (computer == 0) { computerWord = "paper"; } 
      else { 
        if (computer == 1) { computerWord = "rock"; } 
        else { 
          if (computer == 2) { computerWord = "scissors"; } 
          else { computerWord = "... ooops, something went wrong!?"; } 
        } 
      } 
      System.out.print("The computer has chosen " + computerWord + ". What do you choose? "); 
      line = console.readLine(); 
    } 
    System.out.println("Thanks for using this program."); 
  } 
}

::::::::::::::
Quiz.java
::::::::::::::

class Quiz {
  public static void main(String[] args) {
    ConsoleReader console = new ConsoleReader(System.in); 
    int n1, n2, good = 0, total = 0; 
    int answer; 
    String line; 
    
    n1 = (int)(Math.random() * 100 - 50); 
    n2 = (int)(Math.random() * 100 - 50); 

    System.out.print("What is " + n1 + " + " + n2 + "? "); 
    line = console.readLine(); 
    while (! line.equals("done")) {
      answer = Integer.parseInt(line); 
      if (answer == n1 + n2) {
        good += 1; 
      } 
      total += 1; 
      System.out.println("Your current score is: " + good + "/" + total); 
      n1 = (int)(Math.random() * 100 - 50);
      n2 = (int)(Math.random() * 100 - 50);

      System.out.print("What is " + n1 + " + " + n2 + "? ");
      line = console.readLine();
    } 
    System.out.println("Thank you for using this program."); 
  } 
}

::::::::::::::
Reverse.java
::::::::::::::

class Reverse {
    public static void main(String[] args) {
	ConsoleReader c = new ConsoleReader(System.in); 
	String line; 
	System.out.print("Type something: "); 
	line = c.readLine(); 
        while (! line.equals("done")) {
	    int i = line.length() - 1; 
	    System.out.print(line + " reversed is "); 
	    while (i >= 0) {
		System.out.print(line.charAt(i)); 
		i = i - 1; 
	    }
	    System.out.print("\nType something: ");
	    line = c.readLine();
	}
    }
}

::::::::::::::
Square.java
::::::::::::::

class Square {
  public static void main(String[] args) {
    ConsoleReader c = new ConsoleReader(System.in); 
    System.out.print("Please enter a positive number: "); 
    double n = c.readDouble(); 
    double x = 1; 
    while (Math.abs(x * x - n) >= 0.000001) {
      System.out.println("New guess: " + x); 
      x = (x + n / x) / 2;
    } 
    System.out.println(x + " squared is " + x * x); 
  } 
}

::::::::::::::
Vowels.java
::::::::::::::

class Vowels {
  public static void main(String[] args) {
    ConsoleReader console = new ConsoleReader(System.in); 
    String line; 
    System.out.print("Type something: "); 
    line = console.readLine(); 
    int i = 0, j = 0; 
    while (! (line.equals("done"))) {
      j = 0; 
      int v = 0; 
      while (j < line.length()) {
        char c = line.charAt(j); 
        if (c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u' || 
            c == 'A' || c == 'E' || c == 'I' || c == 'O' || c == 'U'    ) {
          v = v + 1; 
        } 
        j = j + 1; 
      } 
      i = i + 1; 
      System.out.println(i + ". " + line + " has " + v + " vowels in it."); 
      System.out.print("Type something: "); 
      line = console.readLine(); 
    } 
  }
}