字典树

最长公共前缀

Find the longest common prefix in an array of strings, returning an empty string if none exists.

单词拆分

Determine if a string can be fully segmented into dictionary words using array scanning and hash-based lookups for effic…

单词拆分 II

Given a string and dictionary, return all possible sentences by adding spaces where each word is in the dictionary.

实现 Trie (前缀树)

This problem requires designing a Trie (Prefix Tree) to efficiently store and query strings using hash table concepts fo…

添加与搜索单词 - 数据结构设计

Build a WordDictionary supporting dynamic word addition and search with wildcard matching efficiently using Trie and DFS…

单词搜索 II

Solve the Word Search II problem using backtracking with pruning to find all words on a board of characters.

回文对

Find all pairs of words in a list that form palindromes when concatenated using efficient scanning and hash mapping.

字典序排数

Generate all numbers from 1 to n in lexicographical order using a depth-first search pattern optimized with trie logic f…

数组中两个数的最大异或值

Find the maximum XOR of two numbers in an integer array using efficient bit manipulation techniques.

字典序的第K小数字

Find the k-th lexicographically smallest integer in a range using a Trie-based approach.

连接词

Find concatenated words by using dynamic programming and depth-first search to identify valid words made of other words …

单词替换

Replace words in a sentence using the shortest root from a dictionary, applying efficient array scanning and hash lookup…

实现一个魔法字典

Design a Magic Dictionary to allow searching with one-character modifications, using Hash Table and String techniques.

键值映射

Design and implement a data structure that supports efficient insertion and sum queries based on string prefixes.

前K个高频单词

Solve Top K Frequent Words by counting each word, then ordering ties alphabetically so frequency wins before lexicograph…

词典中最长的单词

Find the longest word in a dictionary that can be built one character at a time from other words in the dictionary.

前缀和后缀搜索

Design a dictionary to search words by both prefix and suffix using a Trie structure and hash lookups.

匹配子序列的单词数

Given a string s and a list of words, count how many words are subsequences of s using efficient array scanning and hash…

单词的压缩编码

Find the minimum length of a reference string encoding an array of words using array scanning and hash lookup efficientl…

驼峰式匹配

Camelcase Matching is a medium difficulty problem where you match queries to a given pattern by inserting lowercase lett…

字符流

Implement a StreamChecker that detects if any suffix of a character stream matches a given list of words using efficient…

猜字谜

Solve the "Number of Valid Words for Each Puzzle" problem with array scanning and hash lookup to efficiently count valid…

删除子文件夹

Remove sub-folders in a filesystem by filtering out folders nested inside other folders.

搜索推荐系统

Design a search suggestion system that provides the top three lexicographically smallest products matching a search word…