递归

两数相加

Add Two Numbers requires careful linked-list pointer manipulation to sum digits while handling carries efficiently in in…

正则表达式匹配

The Regular Expression Matching problem involves checking if a string matches a pattern using '.' and '*'.

合并两个有序链表

Merge two sorted linked lists by splicing nodes into one sorted list using linked-list pointer manipulation and recursio…

两两交换链表中的节点

Learn how to swap every adjacent linked-list pair by rewiring nodes safely without changing values or breaking the remai…

K 个一组翻转链表

Reverse Nodes in k-Group challenges you to reverse segments of a linked list in groups of size k.

通配符匹配

Implement full wildcard pattern matching using '?' and '*' by applying state transition dynamic programming with careful…

Pow(x, n)

Calculate x to the power n efficiently using recursion and exponentiation, handling negative powers and large inputs saf…

排列序列

Find the kth permutation sequence of a set of numbers using math and recursion to efficiently compute the result.

重排链表

Reorder List requires careful pointer manipulation in a singly linked list to interleave nodes from the ends without alt…

移除链表元素

Remove all nodes from a linked list that have a specific value, adjusting pointers to preserve the rest of the list.

反转链表

Reverse a singly linked list in place, converting the head to tail, with an iterative or recursive approach.

基本计算器

Implement a basic calculator to evaluate mathematical expressions, ensuring correct evaluation with stack-based manageme…

2 的幂

Determine if a given integer is a power of two using efficient math and bit manipulation techniques with optional recurs…

数字 1 的个数

Compute the total number of digit one appearing in all numbers from 0 up to n using state transition dynamic programming…

回文链表

Solve Palindrome Linked List by finding the midpoint, reversing the second half, and comparing mirrored nodes in linear …

为运算表达式设计优先级

Solve Different Ways to Add Parentheses by splitting on each operator and memoizing every subexpression result list.

整数转换英文表示

Convert a given integer to its English words representation using mathematical logic and string manipulation.

3 的幂

Determine if a given integer is a power of three using math and recursion techniques.

4的幂

Determine if a given integer is a power of four using math insights and bit manipulation tricks efficiently in code.

消除游戏

Elimination Game uses a systematic removal of numbers with alternating left-right passes, solvable with math and recursi…

字符串解码

Decode a nested encoded string using stack-based state management, handling repeated patterns efficiently with recursion…

预测赢家

Predict the Winner involves two players taking turns to maximize their score by picking from either end of an array, opt…

斐波那契数

Calculate the nth Fibonacci number using state transition dynamic programming and recursive techniques efficiently in in…

Lisp 语法解析

Parse Lisp expressions using stack-based state management to evaluate variables and operations.