#include <iostream>
#include <omp.h>
#include <cmath>
#include <time.h>
#include <stdio.h>

#define MAXSIZE 3000

void create_array(double array[][MAXSIZE], int n) {
    for (int i=0; i<n; i++) {
        //std::cout << omp_get_thread_num() << std::endl;
        for (int j = 0; j < n; j++) {
            array[i][j] = i*(atan(j) +exp(-(i+j)));
        }
    }
}

void create_array_parallel(double array[][MAXSIZE], int n) {
#pragma omp parallel for
    for (int i=0; i<n; i++) {
        //std::cout << omp_get_thread_num() << std::endl;
        for (int j = 0; j < n; j++) {
            array[i][j] = i*(atan(j) +exp(-(i+j)));
        }
    }
}

double array[MAXSIZE][MAXSIZE];

int main() {
    double start, finish, time_single_thread, time_multi_thread;

    start = omp_get_wtime();
    create_array(array, MAXSIZE);
    finish = omp_get_wtime();
    time_single_thread = finish - start;
    printf("Total runtime with single thread = %lg\n", time_single_thread);

    start = omp_get_wtime();
    create_array_parallel(array, MAXSIZE);
    finish = omp_get_wtime();
    time_multi_thread = finish - start;
    printf("Total runtime with multiple threads = %lg\n", time_multi_thread);
    printf("Speed up = %lg\n", time_single_thread / time_multi_thread);
    printf("Efficiency = %lg\n", time_single_thread / time_multi_thread / 2);

    getchar();

    return 0;
}