#include <stdio.h>
#include <stdlib.h>
#include <omp.h>
#include <math.h>
//#include "pomiar_czasu.h"


double function (double x)
{
    return (5*x)/(sqrt(x));
}

double x1 = 10, x2 = 100, dx, calka = 0;
int i, n = 1000000;

int main(void)
{
    printf("\n ********************************************************* \n ");

    /*printf("\nPodaj x1\n");
    scanf("%f", &x1);

    printf("\nPodaj x2\n");
    scanf("%f", &x2);

    printf("\nPodaj dokladnosc\n");
    scanf("%d", &n);*/

    double start_time = omp_get_wtime();

    dx = (x2-x1) / (double) n;

    //printf("\nSekwencyjnie\n");
    printf("\nParallel - 4 \n");
    #pragma omp parallel for reduction (+: calka) num_threads(4)
    for (i = 1; i < n; ++i) {
      calka += function(x1+i * dx);
    }

    calka += (function(x1) + function(x2)) / 2;
    calka *= dx;

    double time = omp_get_wtime() - start_time;

    printf("\nCalka wynosi: %lf\n", calka);
    printf("\nCzas wynosi: %lf\n", time);

    printf("\n ********************************************************** \n");

    return 0;
}