Array sum in c++ stl

Here is an example of how to calculate the sum of elements in an array using the C++ STL (Standard Template Library):

#include <iostream>
#include <numeric>
#include <vector>

int main() {
    std::vector<int> arr = {1, 2, 3, 4, 5};

    int sum = std::accumulate(arr.begin(), arr.end(), 0);

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

    return 0;
}

Explanation:

• We include the necessary headers: <iostream> for input/output, <numeric> for the accumulate function, and <vector> for the vector container.
• We declare a std::vector<int> called arr and initialize it with some values.
• We use the std::accumulate function from the <numeric> header to calculate the sum of the elements in the vector. This function takes three arguments: the first iterator of the range (in this case, arr.begin()), the last iterator of the range (in this case, arr.end()), and an initial value for the sum (in this case, 0).
• We store the result of the accumulation in the variable sum.
• Finally, we output the sum using std::cout.

This code will output:

Sum: 15

The std::accumulate function takes care of iterating over the elements in the range and adding them up. It is a convenient way to calculate the sum of elements in an array or container using the C++ STL.