midStrings
Find all permutations of a string.
Updated Apr 28, 2026
Short answer
Recursive backtracking to swap characters and generate all unique orderings.
Deep explanation
Intermediate string problems test your ability to use frequency maps and sliding windows. Recursive backtracking to swap characters and generate all unique orderings.
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?