Exercise: Hash Table Problems on LeetCode

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.

1. Two Sum

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128. Longest Consecutive Sequence

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290. Word Pattern

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519. Random Flip Matrix

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138. Copy List with Random Pointer

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133. Clone Graph

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242. Valid Anagram

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49. Group Anagrams

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387. First Unique Character in a String

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169. Majority Element

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389. Find the Difference

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442. Find All Duplicates in an Array

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448. Find All Numbers Disappeared in an Array

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