Calculate the Sum of Elements in an Array (C++)

Understanding Sum Calculation

Finding the sum of elements in an array involves adding all elements together.

We will explore three different methods to determine the sum using C++.

Method 1: Using a Loop

This method iterates through the array and calculates the sum.

#include <iostream>
using namespace std;

int findSum(int arr[], int n) {
    int sum = 0;
    for (int i = 0; i < n; i++) {
        sum += arr[i];
    }
    return sum;
}

int main() {
    int arr[] = {1, 2, 3, 4, 5};
    int n = 5;
    cout << "Sum: " << findSum(arr, n) << endl;
    return 0;
}

Output:
Sum: 15

Method 2: Using Recursion

This method calculates the sum recursively.

#include <iostream>
using namespace std;

int findSum(int arr[], int n) {
    if (n == 0)
        return 0;
    return arr[n - 1] + findSum(arr, n - 1);
}

int main() {
    int arr[] = {1, 2, 3, 4, 5};
    int n = 5;
    cout << "Sum: " << findSum(arr, n) << endl;
    return 0;
}

Output:
Sum: 15

Method 3: Using STL Accumulate

This method uses the accumulate function from the STL.

#include <iostream>
#include <numeric>

using namespace std;

int main() {
    int arr[] = {1, 2, 3, 4, 5};
    int n = 5;
    int sum = accumulate(arr, arr + n, 0);
    cout << "Sum: " << sum << endl;
    return 0;
}

Output:
Sum: 15