Sum of Array

Solved

Difficulty: Basic Accuracy: — Submissions: 0 Points: 1

Given an array arr[] of integers, return the sum of all its elements.

Examples:

Input: arr[] = [1, 2, 3, 4]

Output: 10

Explanation: 1 + 2 + 3 + 4 = 10.

Input: arr[] = [10, -2, 7]

Output: 15

Explanation: 10 + (-2) + 7 = 15.

Constraints:

1 ≤ arr.size() ≤ 10^5
-10^4 ≤ arr[i] ≤ 10^4

Expected Complexities

Time Complexity: O(n) Auxiliary Space: O(1)

Topic Tags

Arrays Basic

Keep a running total and add each element to it. The only trap is overflow: with a hundred thousand values of ten thousand each, the total no longer fits in a 32-bit integer, so use a 64-bit type in C, C++ and Java.

class Solution {
public:
    long long sumOfArray(vector<int>& arr) {
        long long total = 0;
        for (int x : arr) total += x;
        return total;
    }
};