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///
/// @file generate_lpf.cpp
/// @brief Test least prime factor function
///
/// Copyright (C) 2017 Kim Walisch, <kim.walisch@gmail.com>
///
/// This file is distributed under the BSD License. See the COPYING
/// file in the top level directory.
///
#include <generate_primes.hpp>
#include <imath.hpp>
#include <stdint.h>
#include <iostream>
#include <cstdlib>
#include <vector>
#include <random>
using namespace primecount;
void check(bool OK)
{
std::cout << " " << (OK ? "OK" : "ERROR") << "\n";
if (!OK)
std::exit(1);
}
int main()
{
std::random_device rd;
std::mt19937 gen(rd());
std::uniform_int_distribution<int> dist(200000, 300000);
auto max = dist(gen);
auto lpf = generate_lpf(max);
auto primes = generate_primes<int32_t>(max);
for (int i = 2; i <= max; i++)
{
int factor = i;
int sqrt = isqrt(i);
// find smallest prime factor
for (int j = 1; primes[j] <= sqrt; j++)
{
if (i % primes[j] == 0)
{
factor = primes[j];
break;
}
}
std::cout << "lpf(" << i << ") = " << lpf[i];
check(lpf[i] == factor);
}
std::cout << std::endl;
std::cout << "All tests passed successfully!" << std::endl;
return 0;
}
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