🧩 LeetCode Blind 75 Problem Solving

A comprehensive collection of Blind 75 and additional LeetCode problems organized by topic.

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📊 Progress

Category	Blind 75 Completed	Blind 75 Total	Overall Completed	Overall Total
Array	3	13	7	13
Binary	0	5	0	5
Dynamic Programming	1	11	1	12
Graph	0	8	0	8
Interval	1	5	1	5
Linked List	0	6	0	6
Matrix	1	4	1	4
String	5	9	6	10
Tree	0	15	0	15
Heap	0	3	0	3
Total	11	75	16	81

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🟩 Array

#	Problem	Difficulty	Blind 75	Status
1	Two Sum	Easy	✓	✅
11	Container With Most Water	Medium	✓	✅
15	3Sum	Medium	✓	⬜
33	Search in Rotated Sorted Array	Medium	✓	✅
53	Maximum Subarray	Medium	✓	⬜
121	Best Time to Buy and Sell Stock	Easy	✓	⬜
152	Maximum Product Subarray	Medium	✓	⬜
153	Find Minimum in Rotated Sorted Array	Medium	✓	⬜
169	Majority Element	Easy		✅
189	Rotate Array	Medium		⬜
217	Contains Duplicate	Easy	✓	✅
238	Product of Array Except Self	Medium	✓	⬜
283	Move Zeroes	Easy		⬜

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🔢 Binary

#	Problem	Difficulty	Blind 75	Status
190	Reverse Bits	Easy	✓	⬜
191	Number of 1 Bits	Easy	✓	⬜
268	Missing Number	Easy	✓	⬜
338	Counting Bits	Easy	✓	⬜
371	Sum of Two Integers	Medium	✓	⬜

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📈 Dynamic Programming

#	Problem	Difficulty	Blind 75	Status
39	Combination Sum	Medium	✓	✅
55	Jump Game	Medium	✓	⬜
62	Unique Paths	Medium	✓	⬜
70	Climbing Stairs	Easy	✓	⬜
91	Decode Ways	Medium	✓	⬜
139	Word Break	Medium	✓	⬜
198	House Robber	Medium	✓	⬜
213	House Robber II	Medium	✓	⬜
300	Longest Increasing Subsequence	Medium	✓	⬜
322	Coin Change	Medium	✓	⬜
416	Partition Equal Subset Sum	Medium		⬜
1143	Longest Common Subsequence	Medium	✓	⬜

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🗺️ Graph

#	Problem	Difficulty	Blind 75	Status
128	Longest Consecutive Sequence	Medium	✓	⬜
133	Clone Graph	Medium	✓	⬜
200	Number of Islands	Medium	✓	⬜
207	Course Schedule	Medium	✓	⬜
261	Graph Valid Tree 🔒	Medium	✓	⬜
269	Alien Dictionary 🔒	Hard	✓	⬜
323	Number of Connected Components in an Undirected Graph 🔒	Medium	✓	⬜
417	Pacific Atlantic Water Flow	Medium	✓	⬜

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⏱️ Interval

#	Problem	Difficulty	Blind 75	Status
56	Merge Intervals	Medium	✓	✅
57	Insert Interval	Medium	✓	⬜
252	Meeting Rooms 🔒	Easy	✓	⬜
253	Meeting Rooms II 🔒	Medium	✓	⬜
435	Non-overlapping Intervals	Medium	✓	⬜

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🟧 Linked List

#	Problem	Difficulty	Blind 75	Status
19	Remove Nth Node From End of List	Medium	✓	⬜
21	Merge Two Sorted Lists	Easy	✓	🚧
23	Merge K Sorted Lists	Hard	✓	⬜
141	Linked List Cycle	Easy	✓	⬜
143	Reorder List	Medium	✓	⬜
206	Reverse Linked List	Easy	✓	⬜

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🔲 Matrix

#	Problem	Difficulty	Blind 75	Status
48	Rotate Image	Medium	✓	⬜
54	Spiral Matrix	Medium	✓	⬜
73	Set Matrix Zeroes	Medium	✓	⬜
79	Word Search	Medium	✓	✅

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🔤 String

#	Problem	Difficulty	Blind 75	Status
3	Longest Substring Without Repeating Characters	Medium	✓	✅
5	Longest Palindromic Substring	Medium	✓	✅
20	Valid Parentheses	Easy	✓	✅
49	Group Anagrams	Medium	✓	✅
76	Minimum Window Substring	Hard	✓	⬜
125	Valid Palindrome	Easy	✓	✅
242	Valid Anagram	Easy	✓	⬜
271	Encode and Decode Strings 🔒	Medium	✓	⬜
424	Longest Repeating Character Replacement	Medium	✓	⬜
647	Palindromic Substrings	Medium	✓	⬜

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🌳 Tree

#	Problem	Difficulty	Blind 75	Status
98	Validate Binary Search Tree	Medium	✓	⬜
100	Same Tree	Easy	✓	⬜
102	Binary Tree Level Order Traversal	Medium	✓	⬜
104	Maximum Depth of Binary Tree	Easy	✓	⬜
105	Construct Binary Tree from Preorder and Inorder Traversal	Medium	✓	⬜
124	Binary Tree Maximum Path Sum	Hard	✓	⬜
208	Implement Trie (Prefix Tree)	Medium	✓	⬜
211	Design Add and Search Words Data Structure	Medium	✓	⬜
212	Word Search II	Hard	✓	⬜
226	Invert Binary Tree	Easy	✓	⬜
230	Kth Smallest Element in a BST	Medium	✓	⬜
235	Lowest Common Ancestor of a Binary Search Tree	Medium	✓	⬜
297	Serialize and Deserialize Binary Tree	Hard	✓	⬜
572	Subtree of Another Tree	Easy	✓	⬜
543	Diameter of Binary Tree	Easy		⬜

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🏔️ Heap

#	Problem	Difficulty	Blind 75	Status
23	Merge K Sorted Lists	Hard	✓	⬜
295	Find Median from Data Stream	Hard	✓	⬜
347	Top K Frequent Elements	Medium	✓	⬜

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🛠️ Tech Stack

• C# (.NET 8.0)
• Java
• xUnit (Testing)

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📁 Project Structure

├── Basics/          # Java fundamentals
├── Models/          # Shared data structures (ListNode, etc.)
├── Problem Solving/ # C# solutions
└── Test/            # Unit tests

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🚀 Getting Started

# Build the project
dotnet build

# Run tests
dotnet test

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📌 Legend

Symbol	Meaning
✅	Completed
🚧	In Progress
⬜	Not Started