import java.util.Random;
import java.util.Scanner;

/**
 * Write a description of class PiCalc here.
 *
 * @author Mark Davis
 * @version 12/1/2013
 */
public class PiCalc
{
	public static void main(String[] args)
	{
		int[] inputResults = takeInputs();
		int perTrial = inputResults[0];
		int trials = inputResults[1];
		double[] piValues = executeTrials(trials, perTrial);
		System.out.println("Estimated pi = " + computeAverageOfArray(piValues));
	}
	public static int[] takeInputs()
	{
		Scanner in = new Scanner(System.in);
		System.out.println("How many repetitions per trial?");
		String u = in.next();
		int y = Integer.parseInt(u);
		System.out.println("How many Trials?");
		String q = in.next();
		int z = Integer.parseInt(q);
		in.close();
		int[] s = {y,z};
		return s;
	}
	public static double[] executeTrials(int numTrials, int perTrial)
	{
		double[] piValues = new double[numTrials];
		for(int i = 0; (i <= numTrials -1); i++)
		{
			piValues[i] = trial(perTrial);
			System.out.printf("%6s %2s %9s %8.6f", "Trial[", (i + 1), "]: pi = ", piValues[i]);
			System.out.println();
		}
		return piValues;
	}
	public static double trial(int perTrial)
	{
		int numTotal = 0;
		int numInCircle = 0;
		for(int i = 0; (i <= perTrial); i++)
		{
			double a = randomValue(-1.0, 1.0);
			double b = randomValue(-1.0, 1.0);
			if (withinCircle(a,b))
			{
				numInCircle++;
			}
			numTotal++;
		}
		return calcPi(numInCircle, numTotal);
	}
	public static boolean withinCircle(double x, double y)
	{
		if (Math.sqrt(Math.pow(x,2) + Math.pow(y,2)) >= 1)
			return false;
		return true;
	}
	public static double randomValue(double rangeMin, double rangeMax)
	{
		Random r = new Random();
		double randomValue = rangeMin + (rangeMax - rangeMin) * r.nextDouble();
		return randomValue;
	}
	public static double calcPi(int h, int n)

	{
		return ((double)h*4)/((double)n);
	}
	public static double computeAverageOfArray(double[] x)
	{
		double total = 0;
		int depth = 0;
		for(double num: x)
		{
			depth++;
			total += num;
		}
		return total/((double)depth);
	}
}