1. 两数之和 https://leetcode.cn/problems/two-sum
1. Two Sum https://leetcode.com/problems/two-sum
128. 最长连续序列 https://leetcode.cn/problems/longest-consecutive-sequence
128. Longest Consecutive Sequence https://leetcode.com/problems/longest-consecutive-sequence
290. 单词规律 https://leetcode.cn/problems/word-pattern
290. Word Pattern https://leetcode.com/problems/word-pattern
519. 随机翻转矩阵 https://leetcode.cn/problems/random-flip-matrix
519. Random Flip Matrix https://leetcode.com/problems/random-flip-matrix
138. 复制带随机指针的链表 https://leetcode.cn/problems/copy-list-with-random-pointer
138. Copy List with Random Pointer https://leetcode.com/problems/copy-list-with-random-pointer
1490. 克隆 N 叉树 https://leetcode.cn/problems/clone-n-ary-tree
1490. Clone N-ary Tree https://leetcode.com/problems/clone-n-ary-tree
133. 克隆图 https://leetcode.cn/problems/clone-graph
133. Clone Graph https://leetcode.com/problems/clone-graph
242. 有效的字母异位词 https://leetcode.cn/problems/valid-anagram
242. Valid Anagram https://leetcode.com/problems/valid-anagram
49. 字母异位词分组 https://leetcode.cn/problems/group-anagrams
49. Group Anagrams https://leetcode.com/problems/group-anagrams
387. 字符串中的第一个唯一字符 https://leetcode.cn/problems/first-unique-character-in-a-string
387. First Unique Character in a String https://leetcode.com/problems/first-unique-character-in-a-string
169. 多数元素 https://leetcode.cn/problems/majority-element
169. Majority Element https://leetcode.com/problems/majority-element
389. 找不同 https://leetcode.cn/problems/find-the-difference
389. Find the Difference https://leetcode.com/problems/find-the-difference
442. 数组中重复的数据 https://leetcode.cn/problems/find-all-duplicates-in-an-array
442. Find All Duplicates in an Array https://leetcode.com/problems/find-all-duplicates-in-an-array
448. 找到所有数组中消失的数字 https://leetcode.cn/problems/find-all-numbers-disappeared-in-an-array
448. Find All Numbers Disappeared in an Array https://leetcode.com/problems/find-all-numbers-disappeared-in-an-array
Prerequisites
Before reading this article, you should first learn:
Hash tables are a commonly tested data structure in algorithm problems, mainly appearing in data structure design questions or in combination with arrays, strings, and other structures (such as the previous Prefix Sum Exercises). Here are some common hash table questions.