How to parallelize this array sum using OpenMP?

Question

How can I make this array sum is parallelized using OpenMP ? what should be shared, and what should be private ?

Here is the code for array sum ..

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Answer 1

check out this code.

#include <stdio.h>
#include <stdlib.h>
#include <omp.h>
void main()
{
    int sum=0;
    int lsum=0;
    int A[8]={1,2,3,4,5,6,7,8};

    #pragma omp parallel private(lsum)
    {
        int i;
        #pragma omp for
            for (i=0; i<8; i++)
            {
                lsum = lsum +A[i];
            }
        #pragma omp critical
            {
            sum+=lsum;
            }
    }
    printf("%d/n", sum);

}

Answer 2

You should use reduction like this:

#pragma omp parallel for reduction (+:sum)
for (i=0;i<n;i++)
  sum=sum+a[i];