🚀 Blind 75 LeetCode Questions

This repository contains solutions and notes for the Blind 75 LeetCode problems — a curated list of the most important coding interview questions covering essential Data Structures and Algorithms.

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📌 Categories

1. Array / String

• Two Sum (LC 1)
• Best Time to Buy and Sell Stock (LC 121)
• Contains Duplicate (LC 217)
• Product of Array Except Self (LC 238)
• Maximum Subarray (LC 53)
• Maximum Product Subarray (LC 152)
• Find Minimum in Rotated Sorted Array (LC 153)
• Search in Rotated Sorted Array (LC 33)
• 3Sum (LC 15)
• Container With Most Water (LC 11)
• Longest Substring Without Repeating Characters (LC 3)
• Longest Repeating Character Replacement (LC 424)
• Minimum Window Substring (LC 76)
• Valid Anagram (LC 242)
• Group Anagrams (LC 49)
• Valid Parentheses (LC 20)
• Valid Palindrome (LC 125)
• Longest Palindromic Substring (LC 5)
• Palindromic Substrings (LC 647)
• Encode and Decode Strings (LintCode / Premium)

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2. Binary

• Sum of Two Integers (LC 371)
• Number of 1 Bits (LC 191)
• Counting Bits (LC 338)
• Missing Number (LC 268)
• Reverse Bits (LC 190)

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3. Dynamic Programming

• Climbing Stairs (LC 70)
• Coin Change (LC 322)
• Longest Increasing Subsequence (LC 300)
• Longest Common Subsequence (LC 1143)
• Word Break (LC 139)
• Combination Sum IV (LC 377)
• House Robber (LC 198)
• House Robber II (LC 213)
• Decode Ways (LC 91)
• Unique Paths (LC 62)
• Jump Game (LC 55)

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4. Graph

• Clone Graph (LC 133)
• Course Schedule (LC 207)
• Pacific Atlantic Water Flow (LC 417)
• Number of Islands (LC 200)
• Longest Consecutive Sequence (LC 128)
• Alien Dictionary (LC 269 - Premium)
• Graph Valid Tree (LC 261 - Premium)
• Number of Connected Components in an Undirected Graph (LC 323 - Premium)

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5. Interval

• Insert Interval (LC 57)
• Merge Intervals (LC 56)
• Non-overlapping Intervals (LC 435)
• Meeting Rooms (LC 252 - Premium)
• Meeting Rooms II (LC 253 - Premium)

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6. Linked List

• Reverse Linked List (LC 206)
• Merge Two Sorted Lists (LC 21)
• Merge k Sorted Lists (LC 23)
• Remove Nth Node From End of List (LC 19)
• Reorder List (LC 143)

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7. Matrix

• Set Matrix Zeroes (LC 73)
• Spiral Matrix (LC 54)
• Rotate Image (LC 48)
• Word Search (LC 79)

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8. Tree

• Maximum Depth of Binary Tree (LC 104)
• Same Tree (LC 100)
• Invert/Flip Binary Tree (LC 226)
• Binary Tree Maximum Path Sum (LC 124)
• Binary Tree Level Order Traversal (LC 102)
• Serialize and Deserialize Binary Tree (LC 297)
• Subtree of Another Tree (LC 572)
• Construct Binary Tree from Preorder and Inorder Traversal (LC 105)
• Validate Binary Search Tree (LC 98)
• Kth Smallest Element in a BST (LC 230)
• Lowest Common Ancestor of BST (LC 235)
• Implement Trie (Prefix Tree) (LC 208)
• Add and Search Word (LC 211)
• Word Search II (LC 212)

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9. Heap

• Merge k Sorted Lists (LC 23)
• Top K Frequent Elements (LC 347)
• Find Median from Data Stream (LC 295)

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✅ Progress Tracker

• 39 / 75 Completed