public class MonteCarlo {

  public static void main (String[] argv)
  {
    try {
      if ( (argv == null) || (argv.length != 1) ) {
        System.out.println ("Usage: MonteCarlo <numTrials>");
        System.exit(1);
      }

      int numTrials = Integer.parseInt (argv[0]);

      // Initialize count.
      int count = 0;

      // Box dimensions and area.
      double minY = 0;
      double maxY = 1;
      double boxArea = 1.0;

      // Perform trials.
      for (int i=0; i<numTrials; i++) {

        // First pick an x value randomly.
        double x = UniformRandom.uniform();

        // Now pick a y-value randomly in range.
        double y = UniformRandom.uniform (minY, maxY);

        // Check if y < f(x)
        if (y < x*x)
          count ++;

      }
      
      // Apply formula.
      double area = boxArea * ((double) count / (double) numTrials);

      // Output.
      System.out.println ("Area estimate: " + area);
      System.out.println ("Theoretical:   " + (1.0/3.0));
      
    }
    catch (Exception e) {
      e.printStackTrace();
    }
  }
  

}