Leetcode Grind 169 Problems

This curated list contains 169 problems sorted by topic and difficulty to help you systematically grind and improve your problem-solving skills.

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Array

Easy

• 1. Two Sum
• 217. Contains Duplicate
• 283. Move Zeroes
• 704. Binary Search

Medium

• 11. Container With Most Water
• 15. 3Sum
• 16. 3Sum Closest
• 33. Search in Rotated Sorted Array
• 238. Product of Array Except Self
• 53. Maximum Subarray
• 560. Subarray Sum Equals K
• 152. Maximum Product Subarray
• 31. Next Permutation
• 189. Rotate Array

Hard

• 42. Trapping Rain Water
• 41. First Missing Positive
• 239. Sliding Window Maximum

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String

Easy

• 20. Valid Parentheses
• 125. Valid Palindrome
• 242. Valid Anagram
• 844. Backspace String Compare

Medium

• 3. Longest Substring Without Repeating Characters
• 5. Longest Palindromic Substring
• 271. Encode and Decode Strings
• 76. Minimum Window Substring
• 8. String to Integer (atoi)
• 424. Longest Repeating Character Replacement

Hard

• 336. Palindrome Pairs

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Linked List

Easy

• 21. Merge Two Sorted Lists
• 206. Reverse Linked List
• 141. Linked List Cycle
• 876. Middle of the Linked List

Medium

• 19. Remove Nth Node From End of List
• 143. Reorder List
• 24. Swap Nodes in Pairs

Hard

• 23. Merge k Sorted Lists
• 25. Reverse Nodes in k-Group

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Tree

Easy

• 100. Same Tree
• 101. Symmetric Tree
• 104. Maximum Depth of Binary Tree
• 110. Balanced Binary Tree

Medium

• 98. Validate Binary Search Tree
• 102. Binary Tree Level Order Traversal
• 230. Kth Smallest Element in a BST
• 105. Construct Binary Tree from Preorder and Inorder Traversal

Hard

• 124. Binary Tree Maximum Path Sum
• 297. Serialize and Deserialize Binary Tree

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Dynamic Programming

Easy

• 70. Climbing Stairs

Medium

• 91. Decode Ways
• 139. Word Break
• 198. House Robber
• 322. Coin Change
• 300. Longest Increasing Subsequence

Hard

• 312. Burst Balloons

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Graph

Medium

• 133. Clone Graph
• 200. Number of Islands
• 207. Course Schedule
• 210. Course Schedule II

Hard

• 212. Word Search II
• 269. Alien Dictionary

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Matrix

Medium

• 48. Rotate Image
• 54. Spiral Matrix
• 79. Word Search
• 73. Set Matrix Zeroes

Hard

• 85. Maximal Rectangle
• 329. Longest Increasing Path in a Matrix

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Heap

Medium

• 347. Top K Frequent Elements
• 378. Kth Smallest Element in a Sorted Matrix

Hard

• 295. Find Median from Data Stream

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This categorized list of 169 problems is designed to systematically enhance your skills, topic by topic. Tackle them sequentially or focus on your weaker areas!