• Data Structures
• Leetcode Topic Roadmap
  • 1. Arrays & Hashing
  • 2. Two Pointers
  • 3. Stacks
  • 4. Binary Search
  • 5. Sliding Window
  • 6. Linked List
  • 7. Trees
  • 8. Design
  • 9. Tries
  • 10. Backtracking
  • 11. Heap / Priority Queue
  • 12. Graphs
  • 13. 1-D Dynamic Programming
  • 14. Intervals
  • 15. Greedy
  • 16. Advanced Graphs
  • 17. 2-D Dynamic Programming
  • 18. Bit Manipulation
  • 19. Math & Geometry
• Resources

Data Structures

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Data Structure	Code	Search	Insert/Delete	Notes	Language Support
Binary Search Tree	JavaScript	O(log n)	O(log n)		C++ (map / set) & Java (TreeMap / TreeSet)
Dyanmic Array / ArrayList		Unsorted: O(n) / Sorted: O(log n)	Last Value: O(1) / All other values: O(n)		C++ (vector), C# (ArrayList), Java (ArrayList), JavaScript (Array), & Python (list)
Hash Map / Hash Set	JavaScript	O(1)*	O(1)*	Time Complexity is constant on an amortized basis (average)	C++ (unordered_map / unordered_set), C# (Dictionary / Hashtable / HashSet), Java (HashMap / HashSet), JavaScript (Map* / Set*), & Python (dictionary / set)
Linked List	JavaScript	O(n)	O(1)
Min / Max Heap (Priority Queue)		O(n)	O(log n)	Find-min/max: O(1)	C++ (algorithm / make_heap()), Java (PriorityQueue), & Python (heapq)
Queue	JavaScript	O(n)	O(1)	FIFO / LILO (First In First Out / Last In Last Out)	C++ (queue / deque), C# (Queue), Java (ArrayDeque), & Python (deque)
Stack	JavaScript	O(n)	O(1)	FILO / LIFO (First In Last Out / Last In First Out)	C++ (deque / vector / stack), C# (Stack / ArrayList), Java (ArrayDeque / ArrayList / Stack), JavaScript (Array), & Python (list / deque)

Leetcode Topic Roadmap

1. Arrays & Hashing

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Problem	Difficulty	Code Solution	Video Solution
1. Two Sum	Easy	C++ JavaScript Python	YouTube
36. Valid Sudoku	Medium	Python	YouTube
41. First Missing Positive	Hard	Python TypeScript	YouTube
49. Group Anagrams	Medium	Python	YouTube
88. Merge Sorted Array	Easy	Python	YouTube
205. Isomorphic Strings	Easy	Python	YouTube
217. Contains Duplicate	Easy	C++ JavaScript Python	YouTube
347. Top K Frequent Elements	Medium	Python	YouTube
442. Find all Duplicates in an Array	Medium	Python	YouTube
2482. Difference Between Ones and Zeros in Row and Column	Medium	Python	YouTube

2. Two Pointers

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Problem	Difficulty	Code Solution	Video Solution
11. Container With Most Water	Medium	Python	YouTube
15. 3Sum	Medium	Python	YouTube
26. Remove Duplicates from Sorted Array	Easy	JavaScript Python	YouTube
27. Remove Element	Easy	Python	YouTube
28. Find the Index of the First Occurence in a String	Easy	Python TypeScript	YouTube
125. Valid Palindrome	Easy	C++ JavaScript Python	YouTube
167. Two Sum II - Input Array Is Sorted	Medium	JavaScript Python	YouTube
234. Palindrome Linked List	Easy	Python TypeScript	YouTube
344. Reverse String	Easy	C++ JavaScript Python	YouTube
2130. Maximum Twin Sum of a Linked List	Medium	Python	YouTube

3. Stacks

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Problem	Difficulty	Code Solution	Video Solution
20. Valid Parentheses	Easy	C++ JavaScript Python	YouTube
22. Generate Parentheses	Medium	Python	YouTube
94. Binary Tree Inorder Traversal	Easy	Python	YouTube
150. Evaluate Reverse Polish Notation	Medium	Python	YouTube
1047. Remove All Adjacent Duplicates In String	Easy	JavaScript Python	YouTube
1209. Remove All Adjacent Duplicates In String II	Medium	Python	YouTube
1614. Maximum Nesting Depth of the Parentheses	Easy	Python	YouTube
2390. Removing Stars From a String	Medium	Python	YouTube

4. Binary Search

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Problem	Difficulty	Code Solution	Video Solution
34. Find First and Last Position of Element in Sorted Array	Medium	Python	YouTube
35. Search Insert Position	Easy	Python	YouTube
69. Sqrt(x)	Easy	C++ JavaScript Python	YouTube
74. Search a 2D Matrix	Medium	Python	YouTube
162. Find Peak Element	Medium	Python	YouTube
222. Count Complete Tree Nodes	Easy	Python	YouTube
349. Intersection of Two Arrays	Easy	Python	YouTube
374. Guess Number Higher or Lower	Easy	JavaScript Python	YouTube
700. Search in a Binary Search Tree	Easy	Python	YouTube
704. Binary Search	Easy	JavaScript	YouTube

5. Sliding Window

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Problem	Difficulty	Code Solution	Video Solution
3. Longest Substring Without Repeating Characters	Medium	Python	YouTube
121. Best Time to Buy and Sell Stock	Easy	JavaScript Python	YouTube
643. Maximum Average Subarray I	Easy	Python	YouTube
1456. Maximum Number of Vowels in a Substring of Given Length	Medium	Python	YouTube
1658. Minimum Operations to Reduce X to Zero	Medium	Python	YouTube

6. Linked List

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Problem	Difficulty	Code Solution	Video Solution
2. Add Two Numbers	Medium	Python	YouTube
19. Remove Nth Node From End of List	Medium	Python	YouTube
21. Merge Two Sorted Lists	Easy	JavaScript Python	YouTube
83. Remove Duplicates from Sorted List	Easy	JavaScript Python	YouTube
116. Populating Next Right Pointers in Each Node	Medium	Python	YouTube
141. Linked List Cycle	Easy	JavaScript Python	YouTube
206. Reverse Linked List	Easy	Python TypeScript	YouTube
237. Delete Node in a Linked List	Medium	C++	YouTube
287. Find the Duplicate Number	Medium	Python TypeScript	YouTube

7. Trees

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Problem	Difficulty	Code Solution	Video Solution
98. Validate Binary Search Tree	Medium	C++	YouTube
100. Same Tree	Easy	C++ JavaScript Python	YouTube
102. Binary Tree Level Order Traversal	Medium	C++ Python	YouTube
103. Binary Tree Zigzag Level Order Traversal	Medium	Python	YouTube
104. Maximum Depth of Binary Tree	Easy	C++ JavaScript	YouTube
112. Path Sum	Easy	Python	YouTube
230. Kth Smallest Element in a BST	Medium	Python	YouTube
863. All Nodes Distance K in Binary Tree	Medium	Java Python	YouTube
1038. Binary Search Tree to Greater Sum Tree	Medium	C++	YouTube
1302. Deepest Leaves Sum	Medium	C++ JavaScript	YouTube

8. Design

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Problem	Difficulty	Code Solution	Video Solution
146. LRU Cache	Medium	Python	YouTube
155. Min Stack	Medium	C++ Python	YouTube
303. Range Sum Query - Immutable	Easy	Python	YouTube
380. Insert Delete GetRandom O(1)	Medium	C++ Python TypeScript	YouTube
535. Encode and Decode TinyURL	Medium	Python	YouTube
703. Kth Largest Element in a Stream	Easy	Python	YouTube
933. Number of Recent Calls	Easy	Python	YouTube
1603. Design Parking System	Easy	C++	YouTube

9. Tries

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Problem	Difficulty	Code Solution	Video Solution
14. Longest Common Prefix	Easy	Python	YouTube

10. Backtracking

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Problem	Difficulty	Code Solution	Video Solution
17. Letter Combinations of a Phone Number	Medium	Python	YouTube
46. Permutations	Medium	Python	YouTube
77. Combinations	Medium	Python	YouTube
78. Subsets	Medium	Python	YouTube

11. Heap / Priority Queue

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Problem	Difficulty	Code Solution	Video Solution
215. Kth Largest Element in an Array	Medium	Python	YouTube
973. K Closest Points to Origin	Medium	Python	YouTube

12. Graphs

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Problem	Difficulty	Code Solution	Video Solution
127. Word Ladder	Hard	Python	YouTube
200. Number of Islands	Medium	Java JavaScript Python	YouTube
207. Course Schedule	Medium	Python	YouTube
399. Evaluate Divison	Medium	Python	YouTube
695. Max Area of Island	Medium	Java Python	YouTube

13. 1-D Dynamic Programming

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Problem	Difficulty	Code Solution	Video Solution
5. Longest Palindromic Substring	Medium	Python	YouTube
32. Longest Valid Parentheses	Hard	Python	YouTube
70. Climbing Stairs	Easy	JavaScript	YouTube
322. Coin Change	Medium	Python TypeScript	YouTube
392. Is Subsequence	Easy	Python	YouTube
746. Min Cost Climbing Stairs	Easy	Python	YouTube

14. Intervals

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Problem	Difficulty	Code Solution	Video Solution
56. Merge Intervals	Medium	Python	YouTube

15. Greedy

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Problem	Difficulty	Code Solution	Video Solution
53. Maximum Subarray	Medium	C++ JavaScript Python	YouTube
122. Best Time to Buy and Sell Stock II	Medium	JavaScript Python	YouTube
134. Gas Station	Medium	Python	YouTube
680. Valid Palindrome II	Easy	Python	YouTube
1802. Maximum Value at a Given Index in a Bounded Array	Medium	Python	YouTube
2405. Optimal Partition of String	Medium	C++ Python	YouTube
2571. Minimum Operations to Reduce an Integer to 0	Medium	Python	YouTube

16. Advanced Graphs

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Problem	Difficulty	Code Solution	Video Solution
1584. Min Cost to Connect All Points	Medium	Python	YouTube

17. 2-D Dynamic Programming

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Problem	Difficulty	Code Solution	Video Solution
62. Unique Paths	Medium	Python	YouTube
64. Minimum Path Sum	Medium	Python	YouTube

18. Bit Manipulation

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Problem	Difficulty	Code Solution	Video Solution
7. Reverse Integer	Medium	Python	YouTube
67. Add Binary	Easy	Python	YouTube
136. Single Number	Easy	C# JavaScript Python	YouTube
190. Reverse Bits	Easy	Python	YouTube
191. Number of 1 Bits	Easy	Python	YouTube
268. Missing Number	Easy	Python	YouTube
338. Counting Bits	Easy	Python	YouTube
2433. Find The Original Array of Prefix Xor	Medium	Python	YouTube

19. Math & Geometry

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Problem	Difficulty	Code Solution	Video Solution
9. Palindrome Number	Easy	C++	YouTube
13. Roman to Integer	Easy	C++ Java JavaScript	YouTube
48. Rotate Image	Medium	Python	YouTube
66. Plus One	Easy	Python	YouTube
73. Set Matrix Zeroes	Medium	Python	YouTube
202. Happy Number	Easy	JavaScript Python	YouTube
258. Add Digits	Easy	JavaScript Python	YouTube
412. Fizz Buzz	Easy	C++ Java JavaScript Python TypeScript	YouTube
509. Fibonacci Number	Easy	C++ JavaScript	YouTube
1492. The kth Factor of n	Medium	Python	YouTube

Resources

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Website	Description
Pramp	Free Interview Practice
GitHub	Skill Assessment Quizzes
UNLV	Resume and Interview Tips
Levels.fyi	Compensation Information