Strings -> Trie

Prefix trees for dictionary queries, prefix counting, lexicographic traversal, and automaton building blocks.

• Topic slug: strings/trie
• Tutorial page: Open tutorial
• Ladder page: Open ladder
• Repo problems currently tagged here: 2
• Repo companion pages: 0
• Curated external problems: 4

Microtopics

• prefix-tree
• dictionary-queries
• terminal-nodes
• alphabet-optimization
• lexicographic-traversal
• compressed-trie

Learning Sources

Source	Type
Princeton Tries	Course
USACO Guide string searching	Reference

Practice Sources

Source	Type
CSES Word Combinations	Practice
CSES Finding Patterns	Practice

Curated External Problems

Core

Problem	Source	Difficulty	Context	Style	Prerequisites	Tags	Why it fits
Watto and Mechanism	Codeforces	Medium	Hashing	Implementation; Branching Search	Trie Basics; Edit-Distance-1 Checking	Approximate Matching; One-Edit; Dictionary; Lookup	A very common trie exercise with one-character-mismatch queries.
Word Combinations	CSES	Medium	DP	Dynamic Programming; Data-Structure-Heavy	Trie Basics; DP On Prefixes	Dictionary Matching; Dictionary; Prefixes; Counting	A classic trie-plus-DP word segmentation problem.
trie	Library Checker	Medium	Data-Structure	-	-	Insert; Lookup	Pure trie implementation benchmark with the cleanest possible scope.

Challenge

Problem	Source	Difficulty	Context	Style	Prerequisites	Tags	Why it fits
A Lot of Games	Codeforces	Hard	Game-Theory	Game-State Analysis	Trie; Winning/Losing States	Games; Winning-States; Game-DP; Prefix-Tree	Trie structure is the whole game board here.

Repo Problems

Code	Title	Fit	Difficulty	Pattern	Note	Solution
FINDINGPATTERNS	Finding Patterns	secondary	medium	aho-corasick automaton; failure links; multi-pattern presence queries	Note	Code
WORDCOMBINATIONS	Word Combinations	primary	medium	trie plus dp; dictionary segmentation; suffix counting	Note	Code

Regeneration

python3 scripts/generate_problem_catalog.py