46 lines
1.7 KiB
C++
46 lines
1.7 KiB
C++
#include "bsp_5_3_lib.h"
|
|
#include "mayer_primes.h"
|
|
#include <iostream>
|
|
#include <algorithm>
|
|
#include <chrono>
|
|
// BSP 5_3 Goldbach conjunction
|
|
using namespace std;
|
|
|
|
int main()
|
|
{
|
|
omp_set_num_threads(8);
|
|
|
|
cout << "\nChecking for correct result\n";
|
|
cout << "694 has " << single_goldbach_par(694) << " decompositions" << endl;
|
|
|
|
// Auswertung für n=100000 bzw herausfinden der Zahl, welche die meisten Dekompositionen hat
|
|
vector<int> v = count_goldbach_par(1e5);
|
|
auto ip = max_element(v.begin(), v.end());
|
|
cout << "number in [4,1e5] with most decompositions: " << distance(v.begin(), ip)*2+4 << " has " << *ip << " decompositions" << endl;
|
|
|
|
cout << "\nTiming for parallel" << endl;
|
|
vector<int> nvec{static_cast<int>(1e4), static_cast<int>(1e5), static_cast<int>(4*1e5), static_cast<int>(1e6), static_cast<int>(2*1e6)}; // Vektor für n
|
|
for(size_t k=0; k<nvec.size(); ++k)
|
|
{
|
|
auto timestart = omp_get_wtime();
|
|
vector<int> vall = count_goldbach_par(nvec[k]);
|
|
auto time = omp_get_wtime() - timestart;
|
|
cout << "n = " << nvec[k] << "\ttime in s: " << time << endl;
|
|
}
|
|
|
|
cout << "\nTiming for serial" << endl;
|
|
for(size_t k=0; k<nvec.size(); ++k)
|
|
{
|
|
auto timestart = omp_get_wtime();
|
|
vector<int> vall = count_goldbach(nvec[k]);
|
|
auto time = omp_get_wtime() - timestart;
|
|
cout << "n = " << nvec[k] << "\ttime in s: " << time << endl;
|
|
}
|
|
|
|
// for large n the parallel version is slower than the sequential
|
|
// the reason is the reduction(VecAdd) which is slow especially for large vectors
|
|
|
|
// cout << single_goldbach(694) << endl;
|
|
// cout << count_goldbach(10000)[690/2] << endl;
|
|
return 0;
|
|
}
|