import java.io.PrintWriter;
import java.io.FileOutputStream;
import java.io.FileNotFoundException;

public class Random
{
   private double nextNextGaussian;
   private boolean haveNextNextGaussian = false;

   public double nextGaussian() {
       if (haveNextNextGaussian) {
          haveNextNextGaussian = false;
          return nextNextGaussian;
       } else {
          double v1, v2, s;
          do {
              v1 = 2 * Math.random() - 1;   // between -1.0 and 1.0
              v2 = 2 * Math.random() - 1;   // between -1.0 and 1.0
              s = v1 * v1 + v2 * v2;
          } while (s >= 1 || s == 0);

          double multiplier = StrictMath.sqrt(-2 * StrictMath.log(s)/s);
          nextNextGaussian = v2 * multiplier;
          haveNextNextGaussian = true;
         return v1 * multiplier;
      }
   }

   public static void main ( String[] args ) {
      String fileName = "default.dat";
      int    count    = 100;
      double d = 0.0;
      Random r = new Random();

      PrintWriter output = null;

      if ( args.length > 0 ) {
         fileName = args[0];

         if ( args.length > 1 ) {
            try {
                count = Integer.parseInt(args[1]);
            } catch ( NumberFormatException nfe ) {
                System.err.println("Invalid number format for count, defaulting to " + count + ".");
            }

            if ( count <= 0 ) {
                System.err.println("Error: count must be positive.");
                System.exit(-1);
            }
         }
      }

      try {
         output = new PrintWriter( new FileOutputStream(fileName) ) ;
      } catch ( FileNotFoundException fnfe ) {
          System.err.println("Error: could not open " + fileName + " for writing.");
          System.exit(-1);
      }

      for ( int i = 0; i < count; i++ ) {
         output.println("" + r.nextGaussian());
      }

      output.close();
   }
}