PiExperimentRunner.java

public class PiExperimentRunner {

    public static void main(String[] args) {
        // --- Configuration ---
        long[] pointConfigs = {100_000L, 1_000_000L, 10_000_000L};
        int[] threadConfigs = {2, 4, 8};
        int tasks = 100;

        System.out.printf("%-15s %-10s %-12s %-12s %-15s %-15s%n",
                "Type", "Threads", "Points", "Time(ms)", "Estimate", "Error");
        System.out.println("-------------------------------------------------------------------------------------");

        // 1. Run Sequential
        PiEstimator sequential = new SequentialPiEstimator();
        for (long n : pointConfigs) {
            runExperiment("Sequential", sequential, new SimulationConfig(n, 1, 1));
        }

        System.out.println("-------------------------------------------------------------------------------------");

        // 2. Run Parallel
        PiEstimator parallel = new ParallelPiEstimator();
        for (long n : pointConfigs) {
            for (int t : threadConfigs) {
                runExperiment("Parallel", parallel, new SimulationConfig(n, tasks, t));
            }
        }

        System.out.println("-------------------------------------------------------------------------------------");

        // 3. Bonus: Batch Experiments
        System.out.println("BONUS: Running Batch Experiments (Averaging 10 runs)");
        SimulationConfig batchConfig = new SimulationConfig(1_000_000L, 20, 4);
        runBatchExperiments(new ParallelPiEstimator(), batchConfig, 10);
    }

    // --- Helper Methods ---

    private static void runExperiment(String type, PiEstimator estimator, SimulationConfig config) {
        long startTime = System.currentTimeMillis();
        double piEstimate = estimator.estimatePi(config);
        long endTime = System.currentTimeMillis();
        long duration = endTime - startTime;
        double error = Math.abs(piEstimate - Math.PI);

        System.out.printf("%-15s %-10d %-12d %-12d %-15.8f %-15.8f%n",
                type, config.getNumThreads(), config.getTotalPoints(), duration, piEstimate, error);
    }

    private static void runBatchExperiments(PiEstimator estimator, SimulationConfig config, int trials) {
        double totalPi = 0;
        double totalTime = 0;

        for (int i = 0; i < trials; i++) {
            long start = System.currentTimeMillis();
            double result = estimator.estimatePi(config);
            long time = System.currentTimeMillis() - start;

            totalPi += result;
            totalTime += time;
        }

        double avgPi = totalPi / trials;
        double avgTime = totalTime / trials;
        double avgError = Math.abs(avgPi - Math.PI);

        System.out.printf("   > Batch Result (%d trials): Avg Time: %.2f ms | Avg Pi: %.7f | Avg Error: %.7f%n",
                trials, avgTime, avgPi, avgError);
    }
}