1. // parse input 

2. // retrieve state 

   if (state exists) { 
     // process state (could print in the process) 
   } else { 
     // initialize state  
   } 

3. // store state 

4. // show state 

5. // prepare for new input 

Take a look at the example we developed in Java.

import java.io.*; // I/O package needed 

class State {

    String message; // describes the state of the game 
    int acc;        // the actual state of the game  
    String turn;    // part of the state used internally 

    State() {
        this.message = "Welcome to the game, enter a number."; 
        this.acc = 0; 
        this.turn = "user"; // user is always the first to move 
    }

    void process(int arg) {

        if (arg >= 1 && arg <= 10) { // this comes from the user 

    	    this.change(arg); // see below 

            this.showAccumulator(); // print part of state 
	    this.showTurn();        // print part of state 

	    if (this.acc == 0) { } // game has ended!...  
	    else {
		int comp = (int)(Math.random() * 10 + 1); 
		System.out.println("Computer is adding: " + comp); // other printing 

		this.change(comp);
	    }
	} else {
	    System.out.println("Sorry, " + arg + " not a valid input value."); 
	}

    }

    void change(int arg) { // arg is the input, state is this  

        this.acc += arg; // check for legal moves elsewhere (in process, for example) 

        if (this.acc >= 100) {
            this.message = "The " + this.turn + " has won.\nNew game, enter number.";  
            this.acc = 0; 
            this.turn = "user"; // new game 
	} else {
            this.message = "Game is in progress..."; 
	    if (turn.equals("user")) { turn = "computer"; } 
            else { turn = "user"; }
	}
    }

    void printMessage() { System.out.println(this.message); } 

    void showAccumulator() { System.out.println("Current accumulator: " + this.acc); } 

    void showTurn() { System.out.println("The " + this.turn + " moves."); }

    void printState() {
        this.printMessage(); 
	this.showAccumulator();
	this.showTurn();
    }
}

class Program {

    public static void main(String[] args) {

	ConsoleReader c = new ConsoleReader(System.in);
	State a = null;
        String arg = ""; // input 

 
        int num_arg;  // converted input 

	while (true) {

	    try {
		num_arg = Integer.parseInt(arg);
	    } catch (Exception e) {
		num_arg = 0;
	    }

            // get state: a is it, perhaps you can't retrieve it, 
            // because you're at the beginning so in that case init.
            if (a == null) { 
                a = new State(); // initialize 
            } else { 
              a.process(num_arg); // process state (could print in the process...)

              // don't process the newly initialized state (there's nothing to it)
            }  

	    a.printState();
            // store state: a is it 
            System.out.print("------------------------------------\n" + 
                             "Enter a number: "); // prepare the new input 

            arg = c.readLine(); 
	} 
    } // main 

}

class ConsoleReader { 
    ConsoleReader(InputStream inStream) { // constructor 
	reader = new BufferedReader(
                   new InputStreamReader(
                     inStream));     
    }
    String readLine() { // instance method 
	String inputLine = "";
	try {
	    inputLine = reader.readLine(); 
	} catch (IOException e) {
	    System.out.println(e); 
	    System.exit(1); 
	} 
	return inputLine; 
    }
    int readInt() { // instance method 
	String inputString = readLine(); 
	int n = Integer.parseInt(inputString); 
	return n; 
    }
    double readDouble() { // instance method 

	String inputString = readLine(); 
	double x = Double.parseDouble(inputString); 
	return x; 
    } 
    private BufferedReader reader; // instance method 
}