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This tutorial walks through Data Structures & Algorithms in a carefully structured progression — entirely in Swift:

🧮 Foundations

1. Big-O Notation

🧱 Data Structures

1. Arrays & Strings
2. Hash Maps & Hash Sets
3. Linked Lists
4. Stacks
5. Queues & Deques
6. Binary Trees
7. Binary Search Trees
8. Heaps & Priority Queues
9. Tries
10. Graphs
11. Union-Find
12. Segment & Fenwick Trees

🧩 Patterns

1. Two Pointers
2. Sliding Window
3. Fast and Slow Pointers
4. Binary Search
5. DFS and Backtracking
6. BFS
7. Topological Sort
8. Union-Find Pattern
9. Monotonic Stack
10. Prefix Sum
11. Merge Intervals
12. Top-K and Heap Pattern
13. 1D Dynamic Programming
14. 2D Dynamic Programming
15. Greedy
16. Matrix Traversal
17. Bit Manipulation Tricks

🎯 NeetCode 150

Arrays & Hashing

1. Contains Duplicate
2. Valid Anagram
3. Two Sum
4. Group Anagrams
5. Top K Frequent Elements
6. Product of Array Except Self
7. Valid Sudoku
8. Encode and Decode Strings
9. Longest Consecutive Sequence

Two Pointers

1. Valid Palindrome
2. Two Sum II - Input Array Is Sorted
3. 3Sum
4. Container With Most Water
5. Trapping Rain Water

Sliding Window

1. Best Time to Buy and Sell Stock
2. Longest Substring Without Repeating Characters
3. Longest Repeating Character Replacement
4. Permutation in String
5. Minimum Window Substring
6. Sliding Window Maximum

Stack

1. Valid Parentheses
2. Min Stack
3. Evaluate Reverse Polish Notation
4. Generate Parentheses
5. Daily Temperatures
6. Car Fleet
7. Largest Rectangle in Histogram

Binary Search

1. Binary Search
2. Search a 2D Matrix
3. Koko Eating Bananas
4. Search in Rotated Sorted Array
5. Find Minimum in Rotated Sorted Array
6. Time Based Key-Value Store
7. Median of Two Sorted Arrays

Linked List

1. Reverse Linked List
2. Merge Two Sorted Lists
3. Reorder List
4. Remove Nth Node From End of List
5. Copy List with Random Pointer
6. Add Two Numbers
7. Linked List Cycle
8. Find the Duplicate Number
9. LRU Cache
10. Merge k Sorted Lists
11. Reverse Nodes in k-Group

Trees

1. Invert Binary Tree
2. Maximum Depth of Binary Tree
3. Diameter of Binary Tree
4. Balanced Binary Tree
5. Same Tree
6. Subtree of Another Tree
7. Lowest Common Ancestor of a Binary Search Tree
8. Binary Tree Level Order Traversal
9. Binary Tree Right Side View
10. Count Good Nodes in Binary Tree
11. Validate Binary Search Tree
12. Kth Smallest Element in a BST
13. Construct Binary Tree from Preorder and Inorder Traversal
14. Binary Tree Maximum Path Sum
15. Serialize and Deserialize Binary Tree

Tries

1. Implement Trie (Prefix Tree)
2. Design Add and Search Words Data Structure
3. Word Search II

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By following this path, you'll go from:

👉 "I memorized 150 answers 😵" to 👉 "I recognize the pattern before I finish reading the problem 💡"