#include <iostream>
#include <vector>
#include <thread>
#include <cstdlib>
#include <ctime>

using namespace std;
using namespace std::chrono;

#define SIZE 2000 //1000 i 2000
#define LICZBA_WATKOW 4 //1, 2 i 4

int A[SIZE][SIZE];
int B[SIZE][SIZE];
int Bt[SIZE][SIZE];
int C[SIZE][SIZE];

void wyzeruj()
{
	for (int i = 0; i < SIZE; i++)
	{
		for (int j = 0; j < SIZE; j++)
		{
			C[i][j] = 0;
		}
	}
}
 
void losowe_wartosci()
{
	srand(10);
	for (int i = 0; i < SIZE; i++)
	{
		for (int j = 0; j < SIZE; j++)
		{
			A[i][j] = rand() % 10;
			B[i][j] = rand() % 10;
		}
	}
}

void transponowanie()
{
	for (int i = 0; i < SIZE; i++)
	{
		for (int j = 0; j < SIZE; j++)
		{
			Bt[i][j] = B[j][i];
		}
	}
}

void pomnoz_macierze(int start, int stop)
{
	for (int i = start; i < stop; i++)
	{
		for (int j = 0; j < SIZE; j++)
		{
			for (int k = 0; k < SIZE; k++)
			{
				C[i][j] += A[i][k] * B[k][j];
			}
		}
	}
}

void pomnoz_macierze_transpon(int start, int stop)
{
	for (int i = start; i < stop; i++)
	{
		for (int j = 0; j < SIZE; j++)
		{
			for (int k = 0; k < SIZE; k++)
			{
				C[i][j] += A[i][k] * Bt[j][k]; //[j][k] bo transponowane
			}
		}
	}
}

void sekwencyjnie()
{
	duration<double> elapsed_seconds;
    time_point<system_clock> begin = system_clock::now();
	pomnoz_macierze(0,SIZE);
    elapsed_seconds = system_clock::now() - begin;
    cout << "Czas wykonania: " << elapsed_seconds.count() << " s" << endl;
}

void sekwencyjnie_transpon()
{
	transponowanie();
	duration<double> elapsed_seconds;
    time_point<system_clock> begin = system_clock::now();
	pomnoz_macierze_transpon(0,SIZE);
    elapsed_seconds = system_clock::now() - begin;
    cout << "Czas wykonania: " << elapsed_seconds.count() << " s" << endl;
}

void watki()
{
	duration<double> elapsed_seconds;
	std::vector<std::thread*> v;
	int rozmiar_paczki = SIZE / LICZBA_WATKOW;
    time_point<system_clock> begin = system_clock::now();
	for (int i = 0; i < LICZBA_WATKOW; i++)
	{
		if (i == LICZBA_WATKOW - 1) //ostatni watek 
		{
			v.push_back(new std::thread{ pomnoz_macierze, i * rozmiar_paczki, SIZE });
		}
		else
		{
			v.push_back(new std::thread{ pomnoz_macierze, i * rozmiar_paczki, i * rozmiar_paczki + rozmiar_paczki });
		}
	}
	for (int i = 0; i < LICZBA_WATKOW; i++)
	{
		v[i]->join();
		delete v[i];
	}
    elapsed_seconds = system_clock::now() - begin;
    cout << "Czas wykonania: " << elapsed_seconds.count() << " s" << endl;
}

void watki_transpon()
{
	transponowanie();
	duration<double> elapsed_seconds;
	std::vector<std::thread*> v;
	int rozmiar_paczki = SIZE / LICZBA_WATKOW;
    time_point<system_clock> begin = system_clock::now();
	for (int i = 0; i < LICZBA_WATKOW; i++)
	{
		if (i == LICZBA_WATKOW - 1) //ostatni watek
		{
			v.push_back(new std::thread{ pomnoz_macierze_transpon, i * rozmiar_paczki, SIZE });
		}
		else
		{
			v.push_back(new std::thread{ pomnoz_macierze_transpon, i * rozmiar_paczki, i * rozmiar_paczki + rozmiar_paczki });
		}
	}
	for (int i = 0; i < LICZBA_WATKOW; i++)
	{
		v[i]->join();
		delete v[i];
	}
    elapsed_seconds = system_clock::now() - begin;
    	cout << "Czas wykonania: " << elapsed_seconds.count() << " s" << endl;
}

void wyswietl()
{
	std::cout << "Macierz C:" << std::endl;
	for (int i = 0; i < 5; i++)
	{
		for (int j = 0; j < 5; j++)
		{
			std::cout << C[i][j] << "\t";
		}
		std::cout << std::endl;
	}
}

int main()
{
	losowe_wartosci();
	wyzeruj();
	//sekwencyjnie();
	//sekwencyjnie_transpon();
	//watki();
	watki_transpon();
	wyswietl();
	return 0;
}