What are the Efficient Ways to Sum the Elements of a std::vector in C ?

Efficient Methods for Summing Elements in a std::vector

In scenarios where you need to ascertain the cumulative sum of elements within a std::vector, several efficient approaches exist.

C 03 Solutions:

1. Classic For Loop:

   int sum_of_elems = 0;
   for (std::vector<int>::iterator it = vector.begin(); it != vector.end(); ++it)
       sum_of_elems += *it;

2. Standard Algorithm:

   #include <numeric>
   
   sum_of_elems = std::accumulate(vector.begin(), vector.end(), 0);

   Note: The final argument's type determines the initial value and result type. For floating-point inputs, use 0.0 instead of 0.

C 11 and Above Extensions:

3. Automatic Vector Type Handling:

   #include <numeric>
   
   sum_of_elems = std::accumulate(vector.begin(), vector.end(),
                                  decltype(vector)::value_type(0));

4. std::for_each Utilization:

   std::for_each(vector.begin(), vector.end(), [&](int n) {
       sum_of_elems += n;
   });

5. Range-Based For Loop:

   for (auto& n : vector)
       sum_of_elems += n;

C 17 and Later Additions:

6. std::reduce with Automatic Result Type:

   #include <numeric>
   
   auto result = std::reduce(v.begin(), v.end());

   This function's overloads enable parallel processing for extensive collections.

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