/******************************************************************************
 * This program computes the number of primes function π(x)
 * using an estimate formula.
 * 
 * Copyright © 2021 Richard Lesh.  All rights reserved.
 *****************************************************************************/

#undef NDEBUG

#include "Utils.hpp"
#include <clocale>
#include <cmath>
#include <codecvt>
#include <fmt/format.h>
#include <fmt/xchar.h>
#include <iostream>
#include <string>

std::locale utf8loc(std::locale(), new std::codecvt_utf8<wchar_t>);
using namespace Utils;
using namespace std;

long π(int x) noexcept {
    return floor(x / (log(x) - 1.0) + 0.5);
}

int main(int argc, char **argv) {
    setlocale(LC_ALL, "en_US.UTF-8");
    wcout.imbue(utf8loc);
    wcin.imbue(utf8loc);

    int x = 10;
    for (int i = 2; i <= 9; ++i) {
        x *= 10;
        wcout << fmt::format(L"π({0:d}) = {1:d}", x, π(x)) << endl;
    }
    return 0;
}