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  1. #include <iostream>
  2. #include <cmath>
  3. #include <mpi.h>
  4. #include <fstream>
  5. #include <vector>
  6. #include <cstdlib> // for system function
  7.  
  8. using namespace std;
  9.  
  10. void writeDataToFile(const string& filename, int x, long double y) {
  11.     ofstream file(filename, ios::app);
  12.     if (file.is_open()) {
  13.         printf("size and time: %f",y);
  14.         file << x << " " << y<<" \n" << endl;
  15.         file.close();
  16.     }
  17.     else {
  18.         cerr << "Unable to open file for writing." <<endl;
  19.     }
  20. }
  21.  
  22. double f(double x) {
  23.     // Функция, которую мы интегрируем
  24.     return cos(6*x)*sin(5*x) + 4;
  25. }
  26.  
  27.  
  28.  
  29. double trapezoidal(double a, double b, int n, double h) {
  30.     double sum = 0.5 * (f(a) + f(b));
  31.  
  32.     for (int i = 1; i < n; ++i) {
  33.         double x = a + i * h;
  34.         sum += f(x);
  35.     }
  36.  
  37.     return sum * h;
  38. }
  39.  
  40. int main(int argc, char** argv) {
  41.  
  42.     const double a = 0.0;
  43.     const double b = 1;
  44.     const int n = 120000; 
  45.  
  46.     int rank, size;
  47.     long double min_start = 120000, max_end = 0, start, end, local_result, total_result;
  48.  
  49.     MPI_Init(&argc, &argv);
  50.     MPI_Comm_rank(MPI_COMM_WORLD, &rank);
  51.     MPI_Comm_size(MPI_COMM_WORLD, &size);
  52.     MPI_Barrier(MPI_COMM_WORLD);
  53.  
  54.     start = MPI_Wtime();
  55.  
  56.     cout << "Process " << rank << " of " << size << " is running." << endl;
  57.  
  58.  
  59.     // Вычисляем локальный результат для каждого процесса
  60.     int local_n = n / size;
  61.     double local_a = a + rank * (b - a) / size;
  62.     double local_b = local_a + (b - a) / size;
  63.     double h = (b - a) / n;
  64.     //local_result = rectangle_integration(local_a, local_b, local_n);
  65.     //local_result = simpson(local_a, local_b, local_n, h);
  66.     local_result = trapezoidal(local_a, local_b, local_n, h);
  67.  
  68.     MPI_Reduce(&local_result, &total_result, 1, MPI_DOUBLE, MPI_SUM, 0, MPI_COMM_WORLD);
  69.     MPI_Barrier(MPI_COMM_WORLD);
  70.     end = MPI_Wtime();
  71.  
  72.  
  73.     if (rank == 0) {
  74.         cout << "Total result: " << total_result << endl;
  75.     }
  76.  
  77.     int numproc;
  78.  
  79.     numproc = size;
  80.  
  81.  
  82.  
  83.     // Find max time
  84.     if (min_start > start) {
  85.         min_start = start;
  86.     }
  87.  
  88.     if (max_end < end) {
  89.         max_end = end;
  90.     }
  91.  
  92.     if (rank == 0) {
  93.         printf("Time taken to process: %f", (max_end - min_start));
  94.     }
  95.     if (rank == 0) {
  96.         writeDataToFile("data.txt", numproc, (max_end - min_start));
  97.     }
  98.     MPI_Finalize();
  99.  
  100.  
  101.  
  102.  
  103.     return 0;
  104. }
Success #stdin #stdout #stderr 0.27s 40768KB
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Standard input is empty
stdout
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Standard output is empty
stderr
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Error: unexpected symbol in "using namespace"
Execution halted
https://ideone.com/hESuG2
language:
R (R 3.5.2)
created:
14 days ago
visibility:
public

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