/**********************************************
Description: This is an interactive program using
             menu and calculator.
***********************************************/

import java.util.Scanner;

public class Interactive {

      public static void main(String args[]) {
          // vars for the repeat loop
          boolean repeat = true;
          char ans;
          
          // var to hold our integer input
          int n;
          // var to hold a float
          float j;
          
          // we need to declare a new scanner object, hence the new keyword
          Scanner sc = new Scanner(System.in);
           
          /*
           * When using a while loop, we need to define some kind of conditional
           * to check against, otherwise it would (or should) just evaluate to true
           * which we don't want because it would, in theory, run forever.
           */
          while (repeat == true){
                  // print out a menu for the user
              System.out.println( "This is a simple Calculator" );
              System.out.println( "\n********Menu********" );
              System.out.println( "1: Add" );
              System.out.println( "2: Subtract" );
              System.out.println( "3: Multiply" );
              System.out.println( "4: Divide" );
              System.out.println( "5: Exit" );
              System.out.println( "********************\n" );
              System.out.println("Choice? >>  ");
              
              // get the input from the user
              n = sc.nextInt();
               
               if ( n == 1 ) {
                   System.out.print( "Please input two integers to add: " );
                   int n1 = sc.nextInt();
                   int n2 = sc.nextInt();
                   System.out.println( n1 + " + " + n2 + " = " + (n1+n2) );
               } else if ( n == 2 ) {
                   System.out.println( "Please input two integers to subtract: " );
                   int n1 = sc.nextInt();
                   int n2 = sc.nextInt();
                   System.out.println( n1 + " - " + n2 + " = " + (n1-n2) );
               } else if ( n == 3 ) {
                   System.out.println( "Please input two integers to multiply: " );
                   int n1 = sc.nextInt();
                   int n2 = sc.nextInt();
                   System.out.println( n1 + " * " + n2 + " = " + (n1*n2) );
               } else if (n == 4 ) {
                   System.out.println( "Please input two integers to divide: ");
                   int n1 = sc.nextInt();
                   int n2 = sc.nextInt();
                   while (n2 == 0) {
                        System.out.println("You cannot divide by zero!\n");
                        System.out.println("Please re-enter your two integers to divide: ");
                        n1 = sc.nextInt();
                        n2 = sc.nextInt();
                   }
                   float tmpn1 = new Float(n1);
                   float tmpn2 = new Float(n2);
                   System.out.println( n1 + " / " + n2 + " = " + (tmpn1/tmpn2) );
               }
               
               do {
                   System.out.println("Would you like to try again?  ");
                   ans = sc.next().charAt(0);
               } while ((ans != 'Y') && (ans != 'y') && (ans != 'N') && (ans != 'n'));
               
               if (ans == 'N' || ans == 'n') {
                   repeat = false;
                   System.out.println("Thanks for trying the Interactive Calculator!\n");
                   System.exit(0);
               }
           }
      }
}