What is the optimal time complexity of solving Calculate the sum of elements in an array?

The optimized solution achieves a time complexity of O(n) by using sorting, mathematical shortcuts, or hash table lookups.

What is the auxiliary space complexity for Calculate the sum of elements in an array?

The space complexity is O(1) since we only use a minimal/constant amount of extra memory for tracking variables (or auxiliary space if dynamic structures are allocated).

What are the typical edge cases we must handle in Calculate the sum of elements in an array?

Key edge cases include empty collections, negative or large bounds causing integer overflow, arrays with only one element, or inputs where target criteria are not met.

How can we optimize the brute force approach for Calculate the sum of elements in an array?

Brute force methods often inspect all possible combinations. We optimize this by sorting the input list to enable binary search, or tracking processed items in a set to avoid redundant nested loop lookups.

Back to Practice Dashboard

Python BasicsEasy

Calculate the sum of elements in an array

Learn how to solve the 'Calculate the sum of elements in an array' problem. This detailed resource details brute force and optimized approaches.

Mode Selected

Problem Statement

Easy

Write a function array_sum(arr) that takes a list of integers arr and returns the sum of all elements in the array. If the array is empty, return 0.

Constraints

•0 <= len(arr) <= 10^5
•-10^9 <= arr[i] <= 10^9

Examples

Example 1

Input

arr = [1, 2, 3, 4, 5]

Output

Explanation

1 + 2 + 3 + 4 + 5 = 15.

Example 2

Input

arr = [-1, -2, -3]

Output

-6

Explanation

-1 + (-2) + (-3) = -6.

Example 3

Input

arr = []

Output

Explanation

Sum of an empty array is 0.

Need a Hint?

Use simple arithmetic operators (like modulo `%`, division `//`), conditional checks, or loops to inspect number properties.

Edge Cases to Watch

Empty list or null input variables
Single item lists/arrays
Extremely large input bounds causing integer or stack overflow

Ready to Solve?

Open the problem in PyRun's browser-based Python editor. Your code runs fully offline — no server required.

Open in Editor