import java.util.*;
import java.io.*;

class FibApp {

  private static Scanner keyboardInput = new Scanner (System.in);
  private static Fib f = new Fib(1);
  private static final int REC = 1;
  private static final int NONREC = 2;
  private static final int ENTER = 3;
  private static final int EXIT = -1;
  private static int n=0;

  // main program
  public static void main(String[] args) throws Exception {

    int choice;
    n = 0;
    while ((choice = displayMenu()) != -1) {
      choiceAction(choice);
    }
  }

  
  // display Menu and get choice
  private static int displayMenu() {
    int tmp = 0;
    try {
      System.out.println("Computing Fibonacci number...");
      System.out.println(REC + " Recursive version");
      System.out.println(NONREC + " Non Recursive version");
      System.out.println(ENTER + " New Number");
      System.out.println(EXIT + " Exit");
      System.out.print("Choose one of the above options: ");
      tmp = keyboardInput.nextInt();
    }
    catch (Exception e) {
      keyboardInput.next();
    }
    return(tmp);
  }

  private static int getInputN() {
    int tmp = 0;
    try {
      System.out.print("Enter the integer: ");
      tmp = keyboardInput.nextInt();
    }
    catch (Exception e) {
      keyboardInput.next();
    }
    return(tmp);
  }

  private static void choiceAction(int choice) {

    switch(choice) {
      case ENTER:
        n = getInputN();
        f = new Fib(n+1);
        break;
      case REC: 
        System.out.println("Recursively: F("+n+") = "+f.recFib(n));
        break;
      case NONREC: 
        System.out.println("Non-recursively: F("+n+") = "+f.fib(n));
        break;
      default: 
        System.out.println("Incorrect option!");
        break;
    }
  }
  
}