wrong_sum.cpp

#include "parallel_sum.h"
#include <omp.h>
#include <iostream>

int parallel_sum(const int arr[], int size, int step_size) {
    int sum = 0;

    #pragma omp parallel
    {
       
        for (int i = 0; i < size; i += step_size) {
            int start = i, end = i + step_size - 1;

            // Ensure end index is within bounds
            if (end >= size) end = size - 1;

            std::cout << "Thread computing Sum(" << start << "," << end << ") from "
                      << omp_get_thread_num() << " of " << omp_get_num_threads() << std::endl;

            #pragma omp task
            {
                int psum = 0;
                std::cout << "Task computing Sum(" << start << "," << end << ") from "
                          << omp_get_thread_num() << " of " << omp_get_num_threads() << std::endl;
                
                for (int j = start; j <= end; j++) {
                    psum += arr[j];
                }

                #pragma omp critical
                {
                    sum += psum;
                }
            }
        }
    }

    return sum;
}


int main(int argc, char* argv[]) {
    #define ARR_SIZE 600
    #define STEP_SIZE 100

    int a[ARR_SIZE];
    
    // Initialize array with values
    for (int i = 0; i < ARR_SIZE; i++) {
        a[i] = 1;
    }

    // Call the parallel sum function
    int sum = parallel_sum(a, ARR_SIZE, STEP_SIZE);

    std::cout << "Sum = " << sum << std::endl;

    return 0;
}