String to Integer (atoi)
Implement the myAtoi(string s) function, which converts a string to a 32-bit signed integer.
The algorithm for myAtoi(string s) is as follows:
1. Ignore any leading whitespace.
2. Check if the next character is '-' or '+'. Assume the result is positive if neither is present.
3. Read the digits until a non-digit character is encountered or the end of the string is reached.
4. Convert the digits into an integer.
5. If the integer is outside the 32-bit signed integer range [-2³¹, 2³¹ - 1], clamp it to the nearest limit.
Return the resulting integer.
Example 1
Input
42
Output
42
Explanation
The string contains only digits, so the converted integer is 42.
Example 2
Input
-42
Output
-42
Explanation
Leading spaces are ignored, then the negative sign is processed before reading the digits.
Constraints
Hints:
Hint 1
Skip all leading whitespace characters before processing the string.
Hint 2
Handle the optional sign, read consecutive digits, and check for integer overflow before updating the result.
Author & Technical Reviewer
Technically reviewed by: ExamAdda Technical Review Team
Technical Reviewers, ExamAdda
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Published
Aug 4, 2026
Last updated
Aug 5, 2026
Content Verification Methodology
Definitions and complexity claims were checked against authoritative computer-science references. Code examples were compiled and tested with standard, boundary and edge-case inputs.
Expected Output