//
// File:  /home/cs255001/demo/atoi/Atoi_1.java
//
// This is a "gentle" introduction to the String => int conversion algorithm
// This program convert a 2 digit number 
//

import java.util.Scanner;
import java.util.Arrays;

public class ConvStr2Digits
{
   public static void main(String[] args)  throws Exception
   {
      Scanner in = new Scanner(System.in);
      String  s  = null;
      int[]   v = new int[2];   // Variable to save int values of the digits
      int     x;

      while ( true )
      {
         System.out.print("\nEnter input: ");

         s = in.next( );     // Read a String from key board

         if ( s.length() != 2 )
         {
            System.out.println("Error: you must use a string of 2 digits !");
         }

         System.out.println("\nASCII codes (in decimal) = " 
                                + (int) s.charAt(0) + "    "
                                + (int) s.charAt(1) );

         /* -------------------------------------------------------
            Convert the ASCII character to 2's compl - per digit
            ------------------------------------------------------- */
         v[0] = s.charAt(0) - '0';
         v[1] = s.charAt(1) - 48;   // 48 = '0' !!!

         System.out.println("  v[0] = " + v[0] + "(=" 
                             + Integer.toBinaryString(v[0]) + "(bin))" 
                        + ", v[1] = " + v[1] + "(="
                             + Integer.toBinaryString(v[1]) + "(bin))" );

         System.out.print("  Converting: " 
			     + Integer.toBinaryString(v[0]) + "(bin)*"
			     + Integer.toBinaryString(10) + "(bin) + "
			     + Integer.toBinaryString(v[1]) + "(bin)");

         x = v[0]*10 + v[1];  // Computation will be performed in BINARY !

         System.out.println(" = " + Integer.toBinaryString(x) + "(bin)" );

         System.out.println("\nInteger value x = " + x );

         /* =============================================================
            Proof this is an integer that you can use in computation
            ============================================================= */
         x = x + 1;
         System.out.println("\nPerforming a calculation with the output:");
         System.out.println("After adding 1, x = " + x + "\n");
      }
   }
}