#include "pch.h"
#include <iostream>
#include <conio.h>
#include <vector>
#include <Windows.h>
#include <thread>
#include <mutex>

using namespace std;

mutex barrier;

void oblicz(double &pi, long long L, long long R)
{
	//long long n = 0;
	//double licz_pi = 0;
	for (long long i = L; i < R; ++i)
	{
		//barrier.lock();
		lock_guard<mutex> block_threads_until_finish_this_job(barrier);
		if (i % 2 == 0)
			pi += 1.0 / (2.0 * i + 1.0);
		else pi += -1.0 / (2.0 * i + 1.0);
		//n++;
		/*if (n > stop)
		{
			break;
		}*/

		//pi = licz_pi;
		//barrier.unlock();
	}
	//printf("%.16f\n", pi * 4);
}

int main()
{
	double pi = 0;
	int czasA = 0, czasB = 0, ile = 1;

	unsigned long long ilosc1 = 100000000, ilosc2 = 50000000, ilosc3 = 100000000; //100 000 000

	vector<thread> v;
	vector<long long> v1;
	vector<long long> v2;

	printf("Ile watkow chcesz uzyc: ");
	scanf_s("%d", &ile);

	for (int i = 0; i < ile; i++)
	{
		v1.push_back((ilosc1 / ile) * i);
		v2.push_back((ilosc1 / ile) * (i + 1) - 1);
	}

	vector<double>v3(ile);

	czasA = GetTickCount();

	for(int i = 0; i < ile; i++)
	{
		v.push_back(thread(oblicz, ref(pi), v1.at(i), v2.at(i)));
		v.at(i).join();
		//v3.push_back(pi);
	}

	/*for (int i = 0; i < v3.size() - 1; i++)
	{
		pi += v3.at(i);
	}*/

	/*for (auto &t : v) {
		t.join();
	}*/

	/*for (int i = 0; i < v3.size() - 1; i++)
	{
		pi = v3.at(i);
	}*/

	//oblicz(pi, 0, 100000000);

	czasB = GetTickCount();

	printf("%.16f\n", pi * 4);

	printf("Czas wykonania zadania: %d ms", czasB - czasA);

	_getch();
}