设计

LRU 缓存

Implement an efficient LRU Cache using hash table and doubly-linked list to achieve O(1) operations for get and put.

最小栈

Design a stack with O(1) operations to push, pop, retrieve the top element, and get the minimum element in constant time…

二叉搜索树迭代器

Implement an iterator for in-order traversal of a binary search tree (BST), maintaining traversal state with stack-based…

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…

用队列实现栈

This problem tests your ability to simulate a LIFO stack using two queues while preserving all standard stack operations…

用栈实现队列

Implement a queue using two stacks, focusing on stack-based state management to achieve FIFO behavior in a queue.

窥视迭代器

Design an iterator with peek functionality, adding to the standard next and hasNext operations for efficient element acc…

数据流的中位数

Implement a MedianFinder class that supports adding numbers and finding the median from a data stream.

二叉树的序列化与反序列化

This problem asks to serialize and deserialize a binary tree, requiring an efficient approach to handle traversal and st…

区域和检索 - 数组不可变

The Range Sum Query - Immutable problem involves implementing a data structure to handle range sum queries efficiently.

二维区域和检索 - 矩阵不可变

Design a 2D matrix class that efficiently handles sum queries with O(1) time complexity using a prefix sum approach.

区域和检索 - 数组可修改

Implement a mutable range sum query using efficient design patterns to handle multiple updates and range sum queries.

扁平化嵌套列表迭代器

Implement an iterator to flatten a nested list of integers, accounting for potential nesting levels.

将数据流变为多个不相交区间

The problem involves designing a class to summarize a data stream of non-negative integers as disjoint intervals using b…

设计推特

Design Twitter requires implementing post, follow, unfollow, and news feed retrieval using linked-list pointer manipulat…

O(1) 时间插入、删除和获取随机元素

Implement a data structure supporting insert, delete, and getRandom in average O(1) using array plus hash mapping.

O(1) 时间插入、删除和获取随机元素 - 允许重复

This problem challenges you to design a data structure that supports insertion, removal, and random access with O(1) tim…

打乱数组

Shuffle an Array requires designing a class to randomly permute an integer array while ensuring all permutations are equ…

全 O(1) 的数据结构

Implement a data structure that tracks string counts and retrieves max or min keys efficiently in constant time.

序列化和反序列化二叉搜索树

Design an algorithm to serialize and deserialize a binary search tree with efficient traversal and state tracking.

LFU 缓存

Implement an LFU Cache using linked-list pointer manipulation with constant-time get and put operations for interview sc…

TinyURL 的加密与解密

Design a class that encodes and decodes URLs using a URL shortening approach based on hash tables and strings.

设计循环队列

Design a circular queue that allows efficient FIFO operations using linked-list pointer manipulation to optimize space u…