/******************************************************************************
 * Compute π using the Monte Carlo method.
 * 
 * Copyright © 2017 Richard Lesh.  All rights reserved.
 *****************************************************************************/

import org.pureprogrammer.Utils;

public class ComputePi2 {

    static final int MAX_SAMPLES = 1000000;

    public static void main(String[] args) {
        int insideCount = 0;
        for (int i = 0; i < MAX_SAMPLES; ++i) {
            final double x = Math.random();
            final double y = Math.random();
            if (x * x + y * y <= 1.0) {
                ++insideCount;
            }
        }
        final double pi = ((double)(insideCount) / (double)(MAX_SAMPLES)) * 4;
        System.out.println(Utils.format("pi: {0:.15f}", pi));
        System.out.println(Utils.format("abs(pi - π): {0:.10e}", Math.abs(pi - Math.PI)));
    }
}