/******************************************************************************
 * This program computes the mean and std. dev. of random floats.
 * 
 * Copyright © 2020 Richard Lesh.  All rights reserved.
 *****************************************************************************/

#undef NDEBUG

#include "Utils.hpp"
#include <cmath>
#include <ctime>
#include <fmt/format.h>
#include <iostream>
#include <string>
#include <vector>

using namespace std;

int main(int argc, char **argv) {
    if (argc != 2) {
        cout << "Syntax: " << argv[0] << " sample_size" << endl;
        exit(1);
    }
    int sample_size = Utils::stoiWithDefault(string(argv[1]), 10);

    vector<double> samples = {};
    double sum = 0.0;
    srand(time(0));
    for (int i = 0; i < sample_size; ++i) {
        Utils::push(samples, rand()/(RAND_MAX + 1.0));
        sum += samples[i];
    }
    double mean = sum / sample_size;
    double variance = 0.0;
    for (int i = 0; i < sample_size; ++i) {
        variance += pow(samples[i] - mean, 2.0);
    }
    variance /= sample_size;
    cout << fmt::format("Sample mean: {0:.6f}", mean) << endl;
    cout << fmt::format("Sample std. dev.: {0:.6f}", sqrt(variance)) << endl;
    return 0;
}