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  1. #include <stdio.h>
  2. #include <stdlib.h>
  3. #include <time.h>
  4. #include <mpi.h>
  5.  
  6. #define ARRAY_SIZE 12 // Size of the array
  7.  
  8. int main(int argc, char *argv[]) {
  9.     int rank, size, i;
  10.     int array[ARRAY_SIZE];
  11.     int local_max, global_max = -1;
  12.  
  13.     MPI_Init(&argc, &argv);
  14.     MPI_Comm_rank(MPI_COMM_WORLD, &rank);
  15.     MPI_Comm_size(MPI_COMM_WORLD, &size);
  16.  
  17.     // Initialize random seed based on current time and rank
  18.     srand(time(NULL) + rank * 100); // Add rank to ensure different seeds for different processes
  19.  
  20.     // Generate random numbers for the array on process 0
  21.     if (rank == 0) {
  22.         printf("Array:\n");
  23.         for (i = 0; i < ARRAY_SIZE; i++) {
  24.             array[i] = rand() % 100;
  25.             printf("%d ", array[i]);
  26.         }
  27.         printf("\n");
  28.     }
  29.  
  30.     // Broadcast the array from process 0 to all other processes
  31.     MPI_Bcast(array, ARRAY_SIZE, MPI_INT, 0, MPI_COMM_WORLD);
  32.  
  33.     // Calculate local maximum
  34.     int start_index = (ARRAY_SIZE / size) * rank;
  35.     int end_index = start_index + (ARRAY_SIZE / size);
  36.     local_max = array[start_index];
  37.     for (i = start_index + 1; i < end_index; i++) {
  38.         if (array[i] > local_max) {
  39.             local_max = array[i];
  40.         }
  41.     }
  42.  
  43.     if (rank != 0) {
  44.         // Send local maximum to process 0
  45.         MPI_Send(&local_max, 1, MPI_INT, 0, 0, MPI_COMM_WORLD);
  46.     } else {
  47.         // Process 0 receives local maxima from all other processes
  48.         for (i = 1; i < size; i++) {
  49.             int received_max;
  50.             MPI_Recv(&received_max, 1, MPI_INT, i, 0, MPI_COMM_WORLD, MPI_STATUS_IGNORE);
  51.             if (received_max > global_max) {
  52.                 global_max = received_max;
  53.             }
  54.         }
  55.  
  56.         // Compare the local maximum of process 0 with the global maximum
  57.         if (local_max > global_max) {
  58.             global_max = local_max;
  59.         }
  60.  
  61.         // Print the global maximum on process 0
  62.         printf("Global Maximum: %d\n", global_max);
  63.     }
  64.  
  65.     MPI_Finalize();
  66.  
  67.     return 0;
  68. }
  69.  
Success #stdin #stdout #stderr 0.33s 40696KB
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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 "int main"
Execution halted
https://ideone.com/ldGgVd
language:
R (R 3.5.2)
created:
17 days ago
visibility:
public

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