Problem

Given an array of integers, return the sum of the elements in the array.
Example input: [1, 2, 3, 4]
Example output: 10

Solution

#include <iostream>
#include <vector>

using namespace std;

int sum(vector<int> arr) {
    int sum = 0;
    for (int i = 0; i < arr.size(); i++) {
        sum += arr[i];
    }
    return sum;
}

int main() {
    vector<int> arr = {1, 2, 3, 4};
    cout << sum(arr) << endl;
    return 0;
}

/*

This solution is optimal because it is O(n) time complexity.

*/