Implement a basic version of 'atoi' (String to Integer).

Updated Apr 28, 2026

Short answer

Iterate through digits, handle signs, and accumulate the numeric value.

Deep explanation

Intermediate string problems test your ability to use frequency maps and sliding windows. Iterate through digits, handle signs, and accumulate the numeric value.

Real-world example

Search filters that ignore character order.

Common mistakes

  • Inefficiently sorting strings for an anagram check when a frequency map is O(n).

Follow-up questions

  • What is the time complexity of sorting?

More Strings interview questions

View all →