/*
 *  ===================================================================
 *  GeometricSeries.java : Compute sum of a geometric series of complex
 *                         objects.                  
 *
 *  Written By : Mark Austin                                  May, 2004
 *  ===================================================================
 */

import java.lang.Math;
import java.util.*;
import java.io.*;

public class GeometricSeries {

   public static void main( String args[] ) {
   Complex cA = new Complex();
   int    NoTermsInSeries;
   String sLine;

      // Print Welcome Message 

      System.out.println("Welcome to the Geometriic Series Computer");
      System.out.println("-----------------------------------------");

      // Prompt User for Coefficients in Quadratic Equation...

      System.out.println("Please enter complex number \"a\"");

      // Coefficient cA ....

      System.out.print("Coefficent a : Real : ");
      sLine    = keyboardInput();
      cA.dReal = Double.valueOf(sLine).doubleValue();

      System.out.print("Coefficent a : Imaginary : ");
      sLine         = keyboardInput();
      cA.dImaginary = Double.valueOf(sLine).doubleValue();

      // Number of terms in the series .....

      System.out.print("Please enter number of terms in series \"a\":");
      sLine = keyboardInput();
      NoTermsInSeries = Integer.valueOf(sLine).intValue();

      // Print details of input to screen ...

      System.out.print("The complex no you have entered is :");
      System.out.println("s = " + cA.toString() );
      System.out.println("No of terms in series is = " + NoTermsInSeries );
    
      // Check that NoTermsInSeries is greater than or equal to one..

      if ( NoTermsInSeries < 1 ) {
         System.out.println("ERROS: No of terms in series must be at least one:");
         return;
      } 

      // Use basic for loop to compute sumation of geometric series .....

      System.out.println( "Summation with basic for-loop        " );
      System.out.println( "======================================= " );

         ..... details of code removed (about 10 lines of Java) ......

      // Compute sum of geometric series using Horner's rule ....

      System.out.println( "" );
      System.out.println( "Summation using Horner's formula" );
      System.out.println( "======================================= " );

         ..... details of code removed (about 9 lines of Java) ......

      // Use geometric formula to series sum....

      System.out.println( "" );
      System.out.println( "Summation with geometric-series formula " );
      System.out.println( "======================================= " );

         ..... details of code removed (about 11 lines of Java) ......
   }

   /* 
    *  ===========================================================
    *  Method keyboardInput() : Get line of input from keyboard
    * 
    *  Input  : None.
    *  Output : String sLine -- character string of keyboard input
    *  ===========================================================
    */

    static String keyboardInput() {
    String sLine;

        DataInputStream in = new DataInputStream(System.in);
        try{
            sLine = in.readLine();
            return sLine;
        }
        catch (Exception e){
            return "error";
        }
    }
}