What is the optimal time complexity of solving Calculate the area of a circle?

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 area of a circle?

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 area of a circle?

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 area of a circle?

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.

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Python BasicsEasy

Calculate the area of a circle

Learn how to solve the 'Calculate the area of a circle' problem. This detailed resource details brute force and optimized approaches.

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Problem Statement

Easy

Write a function area_of_circle(radius) that takes a non-negative number radius and returns the area of a circle with that radius, rounded to 2 decimal places.

Use the formula: Area = π × radius². Use math.pi or 3.14159265358979 for π.

Constraints

•0 <= radius <= 10^4

Examples

Example 1

Input

area_of_circle(5)

Output

78.54

Explanation

Area = π × 5² = π × 25 = 78.5398... ≈ 78.54.

Example 2

Input

area_of_circle(1)

Output

3.14

Explanation

Area = π × 1² = π ≈ 3.14.

Example 3

Input

area_of_circle(7)

Output

153.94

Explanation

Area = π × 7² = π × 49 = 153.938... ≈ 153.94.

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

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