readme.md

🥇 NeetCode 150 – Ultimate Interview Prep

A complete roadmap of 150 essential coding interview problems curated by NeetCode.

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📊 Progress Tracker

• ✅ Completed: 0 / 150
• 🎯 Goal: Master all problems

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🧠 Arrays & Hashing (9)

• 1. Two Sum
• 217. Contains Duplicate
• 242. Valid Anagram
• 49. Group Anagrams
• 347. Top K Frequent Elements
• 238. Product of Array Except Self
• 36. Valid Sudoku
• 271. Encode and Decode Strings
• 128. Longest Consecutive Sequence

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🔁 Two Pointers (5)

• 125. Valid Palindrome
• 167. Two Sum II
• 15. 3Sum
• 11. Container With Most Water
• 42. Trapping Rain Water

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📊 Sliding Window (6)

• 121. Best Time to Buy and Sell Stock
• 3. Longest Substring Without Repeating Characters
• 424. Longest Repeating Character Replacement
• 567. Permutation in String
• 76. Minimum Window Substring
• 239. Sliding Window Maximum

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📦 Stack (7)

• 20. Valid Parentheses
• 155. Min Stack
• 150. Evaluate Reverse Polish Notation
• 739. Daily Temperatures
• 853. Car Fleet
• 84. Largest Rectangle in Histogram

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🔍 Binary Search (7)

• 704. Binary Search
• 74. Search a 2D Matrix
• 875. Koko Eating Bananas
• 153. Find Minimum in Rotated Sorted Array
• 33. Search in Rotated Sorted Array
• 981. Time Based Key-Value Store
• 4. Median of Two Sorted Arrays

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🔗 Linked List (11)

• 206. Reverse Linked List
• 21. Merge Two Sorted Lists
• 141. Linked List Cycle
• 143. Reorder List
• 19. Remove Nth Node From End
• 138. Copy List with Random Pointer
• 2. Add Two Numbers
• 287. Find the Duplicate Number
• 146. LRU Cache
• 23. Merge k Sorted Lists
• 25. Reverse Nodes in k-Group

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🌲 Trees (15)

• 226. Invert Binary Tree
• 104. Maximum Depth
• 543. Diameter of Binary Tree
• 110. Balanced Binary Tree
• 100. Same Tree
• 572. Subtree of Another Tree
• 235. LCA of BST
• 102. Level Order Traversal
• 199. Right Side View
• 1448. Count Good Nodes
• 98. Validate BST
• 230. Kth Smallest Element
• 105. Construct Binary Tree
• 124. Binary Tree Maximum Path Sum
• 297. Serialize & Deserialize Binary Tree

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📈 Heap / Priority Queue (7)

• 703. Kth Largest in Stream
• 1046. Last Stone Weight
• 973. K Closest Points
• 215. Kth Largest Element
• 621. Task Scheduler
• 355. Design Twitter
• 295. Find Median from Data Stream

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🌲 Backtracking (10)

• 78. Subsets
• 39. Combination Sum
• 40. Combination Sum II
• 46. Permutations
• 90. Subsets II
• 22. Generate Parentheses
• 79. Word Search
• 131. Palindrome Partitioning
• 17. Letter Combinations
• 51. N-Queens

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Tries (3)

• 208. Implement Trie (Prefix Tree)
• 211. Design Add and Search Words Data Structure
• 212. Word Search II

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📊 Graphs (13)

• 200. Number of Islands
• 695. Max Area of Island
• 133. Clone Graph
• 286. Walls and Gates
• 994. Rotting Oranges
• 417. Pacific Atlantic Water Flow
• 130. Surrounded Regions
• 207. Course Schedule
• 210. Course Schedule II
• 684. Redundant Connection
• 127. Word Ladder
• 787. Cheapest Flights Within K Stops

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🌐 Advanced Graphs (6)

• 332. Reconstruct Itinerary
• 1584. Min Cost to Connect Points
• 778. Swim in Rising Water
• 269. Alien Dictionary
• 743. Network Delay Time
• 1631. Path With Minimum Effort

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📈 Dynamic Programming (1D) (12)

• 70. Climbing Stairs
• 746. Min Cost Climbing Stairs
• 198. House Robber
• 213. House Robber II
• 5. Longest Palindromic Substring
• 647. Palindromic Substrings
• 91. Decode Ways
• 322. Coin Change
• 152. Maximum Product Subarray
• 139. Word Break
• 300. Longest Increasing Subsequence
• 416. Partition Equal Subset Sum

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📊 Dynamic Programming (2D) (11)

• 62. Unique Paths
• 1143. Longest Common Subsequence
• 72. Edit Distance
• 115. Distinct Subsequences
• 97. Interleaving String
• 64. Minimum Path Sum
• 221. Maximal Square
• 494. Target Sum
• 518. Coin Change II
• 309. Best Time to Buy/Sell Stock with Cooldown
• 188. Best Time to Buy/Sell Stock IV

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📦 Greedy (8)

• 53. Maximum Subarray
• 55. Jump Game
• 45. Jump Game II
• 134. Gas Station
• 846. Hand of Straights
• 1899. Merge Triplets to Form Target Triplet
• 678. Valid Parenthesis String
• 763. Partition Labels

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🔢 Intervals (6)

• 56. Merge Intervals
• 57. Insert Interval
• 435. Non-overlapping Intervals
• 252. Meeting Rooms
• 253. Meeting Rooms II
• 1851. Minimum Interval to Include Each Query

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🧮 Math & Geometry (8)

• 48. Rotate Image
• 54. Spiral Matrix
• 73. Set Matrix Zeroes
• 202. Happy Number
• 66. Plus One
• 50. Pow(x, n)
• 43. Multiply Strings
• 2013. Detect Squares

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🔤 Bit Manipulation (7)

• 136. Single Number
• 191. Number of 1 Bits
• 338. Counting Bits
• 268. Missing Number
• 371. Sum of Two Integers
• 190. Reverse Bits
• 201. Bitwise AND of Numbers Range

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🚀 How to Use

• Solve 2–5 problems daily
• Track progress using checkboxes
• Revise weak topics weekly
• Focus on patterns, not memorization

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