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LeetCode Solutions

Arrays & Hashing Roadmap

Overview

Section titled “Overview”

This roadmap groups the Arrays & Hashing topic into a clear build order so the repository can grow in a way that stays beginner-friendly.

Current coverage

Section titled “Current coverage”
  • #1 Two Sum
  • #217 Contains Duplicate
  • #242 Valid Anagram
  • #169 Majority Element
  • #268 Missing Number
  • #349 Intersection of Two Arrays

First batch scaffolded

Section titled “First batch scaffolded”
  • #217 Contains Duplicate
  • #242 Valid Anagram
  • #169 Majority Element
  • #268 Missing Number
  • #349 Intersection of Two Arrays
Section titled “Recommended learning order”
  1. #1 Two Sum
  2. #217 Contains Duplicate
  3. #242 Valid Anagram
  4. #169 Majority Element
  5. #268 Missing Number
  6. #349 Intersection of Two Arrays
  7. #350 Intersection of Two Arrays II
  8. #49 Group Anagrams
  9. #347 Top K Frequent Elements
  10. #238 Product of Array Except Self
  11. #36 Valid Sudoku
  12. #128 Longest Consecutive Sequence
  13. #560 Subarray Sum Equals K
  14. #525 Contiguous Array
  15. #41 First Missing Positive

Next problems to implement fully

Section titled “Next problems to implement fully”
  • #350 Intersection of Two Arrays II
  • #49 Group Anagrams
  • #347 Top K Frequent Elements
  • #238 Product of Array Except Self
  • #36 Valid Sudoku

Content standard for each problem

Section titled “Content standard for each problem”
  • Problem statement and examples
  • Complexity comparison
  • Recommended approach first
  • Multi-language solution tabs
  • Common mistakes
  • Animated walkthrough when the logic benefits from visualization

Notes

Section titled “Notes”

The newly scaffolded problems are intentionally lightweight placeholders. They give the repo working pages and file structure now, while leaving room to add polished explanations and animated walkthroughs next.