Prefix tree (Trie) data structure and string-based problems.
- Trie node structure
- Insert, search, and prefix operations
- Word dictionary problems
- Autocomplete systems
- Longest common prefix
- Word search in matrix
- XOR maximum problems using binary trie
- Trie excels at prefix-based queries
- Each node typically has 26 children (for lowercase letters)
- Space-time tradeoff: uses more space for faster queries
- isEnd flag marks complete words
- Useful for dictionary operations and string matching