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  1. #include <mpi.h>
  2. #include <iostream>
  3. #include <cmath>
  4. #include <ctime>
  5. #include <iomanip>
  6.  
  7. using namespace std;
  8.  
  9. double cpu_time(void);
  10. int prime_number(int n, int id, int numtasks);
  11.  
  12. int main(int argc, char** argv) {
  13.     int rank, size, n_factor = 2, n_lo = 1, n_hi = 100;
  14.     double start_time, end_time;
  15.     int n, primes, primes_part;
  16.  
  17.     MPI_Init(&argc, &argv);
  18.     MPI_Comm_rank(MPI_COMM_WORLD, &rank);
  19.     MPI_Comm_size(MPI_COMM_WORLD, &size);
  20.  
  21.     if (rank == 0) {
  22.         cout << "Pomiar ilosci liczb pierwszych w powiekszajacych sie " << n_factor << "-krotnie podprzedzialach przedzialu [" << n_lo << " , " << n_hi << " ]" << endl;
  23.         cout << "\n";
  24.         cout << "    N_max        Ilosc liczb pierwszych        Czas " << endl;
  25.         cout << "\n";
  26.     }
  27.  
  28.     n = n_lo;
  29.  
  30.     while (n <= n_hi) {
  31.         start_time = MPI_Wtime();
  32.  
  33.         MPI_Bcast(&n, 1, MPI_INT, 0, MPI_COMM_WORLD);
  34.         primes_part = prime_number(n, rank, size);
  35.  
  36.         MPI_Reduce(&primes_part, &primes, 1, MPI_INT, MPI_SUM, 0, MPI_COMM_WORLD);
  37.  
  38.         end_time = MPI_Wtime();
  39.  
  40.         if (rank == 0) {
  41.             cout << "    " << setw(3) << n
  42.                  << "    " << setw(18) << primes
  43.                  << "    " << setw(18) << end_time - start_time << endl;
  44.         }
  45.  
  46.         n = n * n_factor;
  47.     }
  48.  
  49.     MPI_Finalize();
  50.     return 0;
  51. }
  52.  
  53. double cpu_time() {
  54.     return (double)clock() / (double)CLOCKS_PER_SEC;
  55. }
  56.  
  57. int prime_number(int n, int id, int numtasks) {
  58.     int prime;
  59.     int total = 0;
  60.  
  61.     for (int i = id + 2; i <= n; i += numtasks) {
  62.         prime = 1;
  63.         for (int j = 2; j < i; j++) {
  64.             if ((i % j) == 0) {
  65.                 prime = 0;
  66.                 break;
  67.             }
  68.         }
  69.         total = total + prime;
  70.     }
  71.     return total;
  72. }
  73.  
Success #stdin #stdout #stderr 0.27s 40480KB
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Standard input is empty
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Standard output is empty
stderr
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Error: unexpected symbol in "using namespace"
Execution halted
https://ideone.com/wQUXiR
language:
R (R 3.5.2)
created:
2 days ago
visibility:
public

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