rrs_lv4

1. Sadrži ovisnosti, pristupa se prethodnim iteracijama petlji, više iteracija mijenja jednu varijablu.

2. #include <omp.h>
#include <iostream>
#include <time.h>
#include <cstdlib>
using namespace std;
int main(int argc, char* argv[]) {
    int n = 10500;
    //clock_t t1,t2;
    double t1, t2, t3, t4;
    int* v = new int[n];
    int** m = new int*[n];
    for(int i = 0; i < n; ++i)
        m[i] = new int[n];

    int* rezultat = new int[n];
    int zbroj = 0;
    int zbroj_serial = 0;
    srand (time(NULL));
    for(int i=0; i<n; i++){
        v[i] = rand() % 100 + 1;
        rezultat[i] = 0;
    }

    for(int i=0; i<n; i++){
        for(int j=0; j<n; j++) {
             m[i][j] = rand() % 100 + 1;
        }
    }

    omp_set_num_threads(4);
    cout << "Množač: ";
    for(int i=0; i<n; i++){
        //cout<< v[i] << "\t";
    }
    cout << "\n";
    cout << "Matrica_before" << endl;
    for(int i=0; i<n; i++){
        for(int j=0; j<n; j++) {
             //cout << m[i][j] << "\t";
        }
        //cout << "\n";
    }
    cout << "Number_niti_active: " << omp_get_num_threads() ;
    cout << "\n";
    //t1 = clock();
    t1 = omp_get_wtime();
    #pragma omp parallel for firstprivate(zbroj)
    for(int i=0; i<n; i++){
        for(int j=0; j<n; j++) {
            zbroj += v[i]*m[j][i];
        }
        rezultat[i] = zbroj;
        zbroj = 0;
        //cout << "Hi, i am nit: " << omp_get_thread_num() << ". I work with redak " << i << ". Bye!" << "\n";
    }
    //t2 = clock();
    t2 = omp_get_wtime();
    cout << "Rezultati: ";
    for(int i=0; i<n; i++){
        //cout<< rezultat[i] << "\t";
    }
    cout << "\n";
    //cout << "Vrijeme_time: " << ((float)(t2-t1))/CLOCKS_PER_SEC << "\n";
    cout << "Vrijeme_time_parallel: " << t2-t1 << " s" << "\n";

    //serijski dio
    t3 = omp_get_wtime();

    for(int i=0; i<n; i++){
        for(int j=0; j<n; j++) {
            zbroj_serial += v[i]*m[j][i];
        }
        rezultat[i] = zbroj_serial;
        zbroj_serial = 0;
    }
    //t2 = clock();
    t4 = omp_get_wtime();
        cout << "Vrijeme_time_serial: " << t4-t3 << " s" << "\n";
    return 0;
}