fork download
copy 
  1. #include <stdio.h>
  2. #include <mpi.h>
  3. #include <math.h>
  4.  
  5. #define PI 3.14159265358979323846
  6. #define INTERVALS 1000000
  7.  
  8. // Function to compute y-coordinate of the pi curve
  9. double compute_pi(double x) {
  10.     return 4.0 / (1.0 + x * x);
  11. }
  12.  
  13. int main(int argc, char** argv) {
  14.     int rank, size;
  15.     double area = 0.0;
  16.     double width = 1.0 / INTERVALS;
  17.     double x;
  18.  
  19.     // Initialize MPI
  20.     MPI_Init(&argc, &argv);
  21.     MPI_Comm_rank(MPI_COMM_WORLD, &rank);
  22.     MPI_Comm_size(MPI_COMM_WORLD, &size);
  23.  
  24.     // Each process calculates its portion of the area
  25.     for (int i = rank; i < INTERVALS; i += size) {
  26.         x = (i + 0.5) * width;
  27.         area += compute_pi(x);
  28.     }
  29.  
  30.     double total_area;
  31.     // Reduce the partial areas from all processes to get the total area
  32.     MPI_Reduce(&area, &total_area, 1, MPI_DOUBLE, MPI_SUM, 0, MPI_COMM_WORLD);
  33.  
  34.     // Only process 0 prints the result
  35.     if (rank == 0) {
  36.         double pi = total_area * width;
  37.         printf("Approximation of Pi: %.16f\n", pi);
  38.     }
  39.  
  40.     // Finalize MPI
  41.     MPI_Finalize();
  42.     return 0;
  43. }
  44.  
Success #stdin #stdout #stderr 0.3s 40416KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
Standard output is empty
stderr
copy 
Error: unexpected '/' in "/"
Execution halted
https://ideone.com/CHWYaJ
language:
R (R 3.5.2)
created:
10 days ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!