Why Practice Tries?
Tries are the "secret weapon" of string problems. They turn expensive string comparisons into fast tree traversals.
Hand-Picked Problems
| Problem | Difficulty | Key Pattern |
|---|---|---|
| Implement Trie (Prefix Tree) | Medium | Basic Structure |
| Word Search II | Hard | Trie + Backtracking |
| Design Add and Search Words | Medium | DFS on Trie |
| Replace Words | Medium | Prefix Match |
| Search Suggestions System | Medium | Autocomplete |
| Maximum XOR of Two Numbers | Medium | Binary Trie |
| Stream of Characters | Hard | Reverse Trie |
| Map Sum Pairs | Medium | Value Accumulation |
| Palindrome Pairs | Hard | Advanced String Logic |
| Longest Common Prefix | Easy | Tree Breadth |
Interview Tip
When using a Trie, always discuss the Memory Trade-off. A Trie node with 26 children can have many null pointers. 埋