#include <omp.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <math.h>
 
#define MAX 100
#define TESTCOUNT 3
 
double start, end;
 
int* InitMas(int size)
{
	int *mas = (int*)malloc(sizeof(int) * size);
	for (int i = 0; i < size; ++i)
	{
		mas[i] = rand() % MAX;
	}
 
	return mas;
}
 
int DotProduct(int *a, int *b, int size)
{
	int dotProduct = 0;
 
	for (int i = 0; i < size; ++i)
	{
		dotProduct += a[i] * b[i];
	}
 
	return dotProduct;
}
 
int ParalDotProduct(int *a, int *b, int size, int chunk)
{
	int dotProduct = 0;
 
	start = omp_get_wtime();
#pragma omp parallel
	{
#pragma omp for schedule(static, chunk) reduction(+:dotProduct)
		for (int i = 0; i < size; ++i)
		{
			dotProduct += a[i] * b[i];
		}
	}
	end = omp_get_wtime();
	return dotProduct;
}
 
void Run(int *a, int *b, int size, int threadCount)
{
	ParalDotProduct(a, b, size, size / threadCount);
 
	printf("Thread count: %d\n", threadCount);
	printf("%g s\n", end - start);
}
 
int main()
{
	int *a, *b;
	int threadCount;
	double start, end;
 
	srand(time(NULL));
	int size = 1000000;
	for (int i = 0; i < TESTCOUNT; ++i)
	{
		printf("Array size: %d\n", size);
		a = InitMas(size);
		b = InitMas(size);
		InitMas(size);
 
		start = omp_get_wtime();
		DotProduct(a, b, size);
		end = omp_get_wtime();
		printf("Thread count: %d\n", 1);
		printf("%g s\n", end - start);
 
 
		Run(a, b, size, 2);
		Run(a, b, size, 3);
		Run(a, b, size, 4);
		Run(a, b, size, 5);
		Run(a, b, size, 6);
		Run(a, b, size, 7);
		Run(a, b, size, 8);
		Run(a, b, size, 9);
		Run(a, b, size, 10);
 
 
		size *= 10;
	}
	system("PAUSE");
}