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LeetCode

LeetCode 355. Design Twitter

Source: https://leetcode.com/problems/design-twitter/

Design a simplified version of Twitter where users can post tweets, follow/unfollow another user and is able to see the 10 most recent tweets in the user’s news feed. Your design should support the following methods:

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LeetCode

LeetCode 350. Intersection of Two Arrays II

Source: https://leetcode.com/problems/intersection-of-two-arrays-ii/

Given two arrays, write a function to compute their intersection.

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LeetCode

LeetCode 349. Intersection of Two Arrays

Source: https://leetcode.com/problems/intersection-of-two-arrays/

Given two arrays, write a function to compute their intersection.

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LeetCode

LeetCode 347. Top K Frequent Elements

Source: https://leetcode.com/problems/top-k-frequent-elements/

Given a non-empty array of integers, return the k most frequent elements.

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LeetCode

LeetCode 219. Contains Duplicate II

Source: https://leetcode.com/problems/contains-duplicate-ii/

Given an array of integers and an integer k, find out whether there are two distinct indices i and j in the array such that nums[i] = nums[j]and the absolute difference between i and j is at most k.

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LeetCode

LeetCode 217. Contains Duplicate

Source: https://leetcode.com/problems/contains-duplicate/

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LeetCode 202. Happy Number

Source:https://leetcode.com/problems/happy-number/

Write an algorithm to determine if a number is “happy”.

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LeetCode

LeetCode 136. Single Number

Source: https://leetcode.com/problems/single-number/

Given a non-empty array of integers, every element appears twice except for one. Find that single one.

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LeetCode

LeetCode 49. Group Anagrams

Given an array of strings, group anagrams together.

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LeetCode

LeetCode 36. Valid Sudoku

Source: https://leetcode.com/problems/valid-sudoku/

Determine if a 9×9 Sudoku board is valid. Only the filled cells need to be validated according to the following rules:

  1. Each row must contain the digits 1-9 without repetition.
  2. Each column must contain the digits 1-9 without repetition.
  3. Each of the 9 3x3 sub-boxes of the grid must contain the digits 1-9 without repetition.