Longest Common Prefix among an array of strings.

Updated Apr 28, 2026

Short answer

Compare characters index by index across all strings until a mismatch occurs.

Deep explanation

Intermediate string problems test your ability to use frequency maps and sliding windows. Compare characters index by index across all strings until a mismatch occurs.

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?

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