202-快乐数(Happy Number) 原文链接: https://leetcode-cn.com/problems/happy-number 英文原文Write an algorithm to determine if a number n is happy. A hap 2021-12-03 双指针哈希表数学 简单
204-计数质数(Count Primes) 原文链接: https://leetcode-cn.com/problems/count-primes 英文原文Given an integer n, return the number of prime numbers that ar 2021-12-03 数学数组数论枚举 中等
205-同构字符串(Isomorphic Strings) 原文链接: https://leetcode-cn.com/problems/isomorphic-strings 英文原文Given two strings s and t, determine if they are isomorp 2021-12-03 哈希表字符串 简单
206-反转链表(Reverse Linked List) 原文链接: https://leetcode-cn.com/problems/reverse-linked-list 英文原文Given the head of a singly linked list, reverse the lis 2021-12-03 递归链表 简单
207-课程表(Course Schedule) 原文链接: https://leetcode-cn.com/problems/course-schedule 英文原文There are a total of numCourses courses you have to take, l 2021-12-03 图广度优先搜索拓扑排序深度优先搜索 中等
208-实现 Trie (前缀树)(Implement Trie (Prefix Tree)) 原文链接: https://leetcode-cn.com/problems/implement-trie-prefix-tree 英文原文A trie (pronounced as "try") or prefix 2021-12-03 哈希表字典树字符串设计 中等
209-长度最小的子数组(Minimum Size Subarray Sum) 原文链接: https://leetcode-cn.com/problems/minimum-size-subarray-sum 英文原文Given an array of positive integers nums and a po 2021-12-03 二分查找前缀和数组滑动窗口 中等
210-课程表 II(Course Schedule II) 原文链接: https://leetcode-cn.com/problems/course-schedule-ii 英文原文There are a total of numCourses courses you have to take 2021-12-03 图广度优先搜索拓扑排序深度优先搜索 中等
211-添加与搜索单词 - 数据结构设计(Design Add and Search Words Data Structure) 原文链接: https://leetcode-cn.com/problems/design-add-and-search-words-data-structure 英文原文Design a data structure that sup 2021-12-03 字典树字符串深度优先搜索设计 中等
212-单词搜索 II(Word Search II) 原文链接: https://leetcode-cn.com/problems/word-search-ii 英文原文Given an m x n board of characters and a list of string 2021-12-03 回溯字典树字符串数组矩阵 困难