std::plus in c++

// C++ program to illustrate std::plus
// by adding the respective elements of 2 arrays
#include <iostream> // std::cout
#include <functional> // std::plus
#include <algorithm> // std::transform

int main()
{
    // First array
    int first[] = { 1, 2, 3, 4, 5 };

    // Second array
    int second[] = { 10, 20, 30, 40, 50 };

    // Result array
    int results[5];

    // std::transform applies std::plus to the whole array
    std::transform(first, first + 5, second, results, std::plus<int>());

    // Printing the result array
    for (int i = 0; i < 5; i++)
        std::cout << results[i] << " ";

    return 0;
}

// C++ program to illustrate std::plus
// by adding all array elements with a number
#include <bits/stdc++.h>

int main()
{
    // Array with elements to be added
    int arr[] = { 10, 20, 30 };

    // size of array
    int size = sizeof(arr) / sizeof(arr[0]);

    // Variable with which array is to be added
    int num = 100;

    // Variable to store result
    int result;

    // using std::accumulate to perform addition on array with num
    // using std::plus
    result = std::accumulate(arr, arr + size, num, std::plus<int>());

    // Printing the result
    std::cout << "The result of 100 + 10 + 20 + 30 is " << result;

    return 0;
}