String to Integer (atoi)

Problem

Convert a string to a signed 32-bit integer, stopping at the first invalid character.

Examples

Example 1

Input: " -42"

Output: -42

Example 2

Input: "4193 with words"

Output: 4193

Input and output use JSON-compatible values. For linked-list and tree questions, arrays represent the node structure as described above. Your code should implement solve(input).

Write your solutionImplement solve(input). Your draft is saved in this browser.

Compiler

How to solve String to Integer (atoi)

One approach is: Trim leading spaces, read the sign, then digits. The reference code demonstrates this method. Compare the example and edge-case tests, then consider time and space usage.

Time and space complexity

Discuss the dominant operations and any additional data structures used by your implementation.

Practise and improve

Choose JavaScript, TypeScript or Python, complete the starter code, then select Run Tests. Request a hint when you need guidance, or choose View solution and confirm if you would like to study the reference implementation.