Problem

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

Solution

#include <iostream>
#include <vector>

using namespace std;

int main() {
    vector<int> arr = {1, 2, 3, 4};
    int sum = 0;
    for (int i = 0; i < arr.size(); i++) {
        sum += arr[i];
    }
    cout << sum << endl;
    return 0;
}

/*

The solution above is optimal because it uses a single for loop to iterate through the array and add each element to the sum.
The time complexity of this solution is O(n) because the for loop iterates through the array once.

*/