🔥 The Ultimate MAANG+ DSA Interview Prep List (2025) 🚀

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🎯 Goal: This isn't just another list. It's a strategically curated collection of ~100 high-impact Data Structures and Algorithms problems frequently encountered in interviews at MAANG (Meta, Apple, Amazon, Netflix, Google) and other top-tier tech companies. Master these, and you'll build the core problem-solving muscle needed to excel. 💪

💡 How This List Was Curated:

• Cross-Referencing: Problems selected appear consistently across highly respected resources like:
  • LeetCode's "Top Interview Questions" (by frequency).
  • Blind 75: A list crowdsourced from Blind (an anonymous professional network).
  • NeetCode 150: A popular curated list covering essential patterns.
  • Aggregated interview experiences shared on LeetCode Discuss, Glassdoor, and other platforms.
• Concept Coverage: Ensuring all fundamental DSA topics and common patterns are represented.
• MAANG+ Focus: Prioritizing question types and difficulties commonly reported in MAANG+ interviews.
• Community Validation: Incorporating problems widely recognized by the competitive programming and interview prep community.

Disclaimer: While based on extensive research and community data, exact interview questions vary. This list focuses on building the underlying skills tested by recurring problem patterns.

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📚 Table of Contents

Click the links to jump to a section!

1. 📊 Array
2. ✍️ String
3. ⛓️ Linked List
4. ⚖️ Two Pointers
5. 🖼️ Sliding Window
6. 🥞 Stack
7. 🌳 Tree (BFS/DFS/Traversal)
8. 🌲 Tree (Advanced & BST)
9. 🥞 Heap / Priority Queue
10. 🔙 Backtracking
11. 💻 Dynamic Programming (1D)
12. 🧱 Dynamic Programming (2D & Advanced)
13. 🌐 Graph (BFS/DFS/Union-Find)
14. 🗺️ Graph (Advanced & Shortest Path)
15. 🔍 Binary Search
16. 💡 Greedy
17. 📐 Math & Bit Manipulation
18. 🧩 Intervals

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• Legend:
  • 
  • 
  • 
  • ⭐ = Especially High Frequency / Foundational

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📊 Array

#	Problem	Difficulty	Concepts	Why MAANG+ Loves It	Source Hint*
1	⭐ Two Sum		Hashing	The quintessential hash map problem. Checks basic data structure usage.	LC Top, Blind 75
2	⭐ Best Time to Buy and Sell Stock		Sliding Window, Greedy	Simple optimization, finding min/max efficiently in one pass.	LC Top, Blind 75
3	Contains Duplicate		Hashing, Set	Basic set usage for uniqueness checks.	LC Top
4	⭐ Product of Array Except Self		Prefix/Suffix Products	Clever array manipulation without division. Tests thinking outside the box.	LC Top, Blind 75
5	⭐ Maximum Subarray		Kadane's Algo, DP	The most famous DP intro problem (can be solved greedily). Fundamental pattern.	LC Top, Blind 75
6	Maximum Product Subarray		DP, Array Traversal	Variation of Max Subarray, handles negative numbers. Tests edge cases.	LC Top, Blind 75
7	Find Minimum in Rotated Sorted Array		Binary Search	Classic modified binary search on rotated arrays.	LC Top, Blind 75
8	⭐ Search in Rotated Sorted Array		Binary Search	Extends the above, requires careful boundary condition handling.	LC Top, Blind 75
9	⭐ 3Sum		Sorting, Two Pointers	Foundational k-sum problem. Tests handling duplicates and two-pointer technique.	LC Top, Blind 75
10	Container With Most Water		Two Pointers	Classic two-pointer optimization problem.	LC Top, Blind 75
11	Next Permutation		Array Manipulation	Understanding lexicographical order and in-place swaps.	LC Top
12	Find the Duplicate Number		Cycle Detection (Floyd's)	Maps array problem to linked list cycle detection. Clever and efficient.	LC Top

*Source Hint: Indicates sources where this problem is frequently listed (LC Top = LeetCode Top Interview Qs, Blind 75, NeetCode 150). This is indicative, not exhaustive.

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✍️ String

#	Problem	Difficulty	Concepts	Why MAANG+ Loves It	Source Hint*
13	⭐ Longest Substring Without Repeating Characters		Sliding Window, Hashing	The canonical sliding window problem. Tests efficient substring analysis.	LC Top, Blind 75
14	⭐ Longest Repeating Character Replacement		Sliding Window, Hashing	Advanced sliding window requiring careful window condition management.	LC Top, Blind 75
15	⭐ Minimum Window Substring		Sliding Window, Hashing	The definitive challenging sliding window problem. Tests complex state tracking.	LC Top, Blind 75
16	⭐ Valid Anagram		Hashing, Sorting	Fundamental check for character counts. Basic but essential.	LC Top, Blind 75
17	⭐ Group Anagrams		Hashing, Sorting	Grouping items based on a derived key (sorted string or char count). Common pattern.	LC Top, Blind 75
18	⭐ Valid Parentheses		Stack	Classic stack application for matching pairs.	LC Top, Blind 75
19	⭐ Valid Palindrome		Two Pointers, String	Basic two-pointer technique for symmetry checks, ignoring non-alphanumerics.	LC Top, Blind 75
20	⭐ Longest Palindromic Substring		Expand Around Center, DP	Finding optimal substructures. Expand-around-center is often preferred.	LC Top, Blind 75
21	Palindromic Substrings		Expand Around Center, DP	Counting all palindromic substrings. Similar logic to #20 but counting instead of finding max.	LC Top, Blind 75
22	Encode and Decode Strings (Premium)		String Design, Delimiter	Practical problem often asked in system design contexts or phone screens. Tests edge cases.	Blind 75, NeetCode

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⛓️ Linked List

#	Problem	Difficulty	Concepts	Why MAANG+ Loves It	Source Hint*
23	⭐ Reverse Linked List		Iteration, Recursion	The absolute fundamental linked list manipulation.	LC Top, Blind 75
24	⭐ Linked List Cycle		Floyd's Cycle Detection	Classic application of the Tortoise and Hare algorithm.	LC Top, Blind 75
25	⭐ Merge Two Sorted Lists		Pointers, Iteration	Foundational merging logic, basis for Merge Sort.	LC Top, Blind 75
26	⭐ Merge k Sorted Lists		Heap (Priority Queue), D&C	Scalable merging. Tests heap usage or divide-and-conquer approach.	LC Top, Blind 75
27	Remove Nth Node From End of List		Two Pointers (Fast/Slow)	Common two-pointer pattern for finding elements relative to the end.	LC Top, Blind 75
28	Reorder List		Find Middle, Reverse, Merge	Combines multiple core list operations. Good test of modular thinking.	LC Top, Blind 75

(Sections for Two Pointers, Sliding Window, Stack, Trees, Heap, Backtracking, DP, Graphs, Binary Search, Greedy, Math/Bit Manipulation, Intervals would follow a similar detailed format)

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⚖️ Two Pointers

(Problems like 3Sum, Container With Most Water, Valid Palindrome are already listed, but this section could include others primarily solved with this technique if not covered elsewhere)

#	Problem	Difficulty	Concepts	Why MAANG+ Loves It	Source Hint*
29	Sort Colors		Two Pointers	Dutch National Flag problem. Efficient in-place partitioning.	LC Top
30	Trapping Rain Water		Two Pointers, DP, Stack	Multiple solutions exist. Tests optimization and insights.	LC Top, NeetCode

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🖼️ Sliding Window

(Many already covered in Array/String sections, this ensures the pattern is highlighted)

#	Problem	Difficulty	Concepts	Why MAANG+ Loves It	Source Hint*
31	Permutation in String		Sliding Window, Hashing	Fixed-size window check using frequency maps.	LC Top, Blind 75
32	Best Time to Buy and Sell Stock		Sliding Window, Greedy	(Re-listed for pattern emphasis) Simple window optimization.	LC Top, Blind 75
33	Longest Substring Without Repeating Characters		Sliding Window, Hashing	(Re-listed) The classic dynamic window size problem.	LC Top, Blind 75

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🥞 Stack

#	Problem	Difficulty	Concepts	Why MAANG+ Loves It	Source Hint*
34	⭐ Valid Parentheses		Stack	(Re-listed) Fundamental stack usage for matching.	LC Top, Blind 75
35	Min Stack		Stack Design	Designing a stack with O(1) min retrieval. Tests data structure design.	LC Top, NeetCode
36	Evaluate Reverse Polish Notation		Stack	Direct stack application for expression evaluation.	LC Top
37	Daily Temperatures		Monotonic Stack	Classic "next greater element" pattern using a monotonic stack.	LC Top, NeetCode
38	Largest Rectangle in Histogram		Monotonic Stack	Challenging application of monotonic stack for area calculation.	LC Top, NeetCode

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🌳 Tree (BFS/DFS/Traversal)

#	Problem	Difficulty	Concepts	Why MAANG+ Loves It	Source Hint*
39	⭐ Maximum Depth of Binary Tree		DFS, Recursion	Basic recursive tree traversal.	LC Top, Blind 75
40	⭐ Same Tree		DFS, Recursion	Basic structural comparison using recursion.	LC Top, Blind 75
41	⭐ Invert Binary Tree		DFS/BFS, Recursion	Famous, simple tree manipulation via recursion or iteration.	LC Top, Blind 75
42	Subtree of Another Tree		DFS, Recursion	Recursive check involving a helper function for subtree matching.	LC Top, Blind 75
43	⭐ Binary Tree Level Order Traversal		BFS, Queue	The canonical BFS application on trees.	LC Top, Blind 75
44	Binary Tree Right Side View		BFS, DFS	Variation of level order traversal (finding the last node at each level).	LC Top, NeetCode
45	Diameter of Binary Tree		DFS, Recursion	Calculating longest path via recursive depth calculation.	LC Top, NeetCode

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🌲 Tree (Advanced & BST)

#	Problem	Difficulty	Concepts	Why MAANG+ Loves It	Source Hint*
46	⭐ Lowest Common Ancestor of a Binary Search Tree		BST Properties, DFS	Utilizes BST properties for efficient LCA finding.	LC Top, Blind 75
47	⭐ Validate Binary Search Tree		DFS, Recursion, Range	Checking BST validity requires passing down min/max constraints. Important detail.	LC Top, Blind 75
48	⭐ Kth Smallest Element in a BST		Inorder Traversal, DFS	Leverages the inorder traversal property of BSTs.	LC Top, Blind 75
49	Construct Binary Tree from Preorder and Inorder Traversal		Recursion, Hashing	Classic tree construction problem using traversal properties.	LC Top, Blind 75
50	⭐ Binary Tree Maximum Path Sum		DFS, Recursion	Tricky recursion where path can start/end anywhere. Requires careful state return.	LC Top, Blind 75
51	Serialize and Deserialize Binary Tree		DFS/BFS, String	Design problem involving tree representation as a string. Tests clear encoding/decoding.	LC Top, Blind 75
52	Implement Trie (Prefix Tree)		Trie, Design	Foundational for many string/dictionary problems.	LC Top, Blind 75
53	Design Add and Search Words Data Structure		Trie, DFS, Backtracking	Extends Trie with wildcard search. Tests recursive search logic.	LC Top, Blind 75
54	Word Search II		Trie, Backtracking, DFS	Combines Trie efficiency with grid backtracking. Highly practical.	LC Top, Blind 75

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🥞 Heap / Priority Queue

#	Problem	Difficulty	Concepts	Why MAANG+ Loves It	Source Hint*
55	⭐ Top K Frequent Elements		Hashing, Heap, QuickSelect	Finding most frequent items efficiently. Tests Heap or QuickSelect usage.	LC Top, Blind 75
56	Kth Largest Element in an Array		Heap, QuickSelect	Similar to Top K, focuses on finding the specific Kth element.	LC Top, NeetCode
57	Find Median from Data Stream		Two Heaps (Max/Min)	Classic design problem using two heaps to maintain median in a streaming fashion.	LC Top, Blind 75
58	Merge k Sorted Lists		Heap (Priority Queue)	(Re-listed) Efficiently merging multiple lists using a min-heap.	LC Top, Blind 75
59	Task Scheduler		Greedy, Heap, Hashing	Scheduling tasks with cooldowns. Often solved greedily or with a max-heap.	LC Top, NeetCode

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🔙 Backtracking

#	Problem	Difficulty	Concepts	Why MAANG+ Loves It	Source Hint*
60	⭐ Subsets		Backtracking, Recursion	Generating all possible combinations (powerset). Foundational backtracking.	LC Top, Blind 75
61	Combination Sum		Backtracking, Recursion	Finding combinations that sum to a target (with repetition allowed).	LC Top, Blind 75
62	Permutations		Backtracking, Recursion	Generating all orderings of elements.	LC Top, Blind 75
63	Subsets II		Backtracking, Sorting	Subsets problem with duplicate elements. Requires handling duplicates carefully.	LC Top, NeetCode
64	Combination Sum II		Backtracking, Sorting	Combination sum with duplicates, ensuring unique combinations.	LC Top, NeetCode
65	⭐ Word Search		Backtracking, DFS	Classic grid backtracking problem. Searching for a word in a 2D board.	LC Top, Blind 75
66	Letter Combinations of a Phone Number		Backtracking, Recursion	Mapping digits to letters and generating combinations. Common recursive structure.	LC Top, NeetCode
67	N-Queens		Backtracking	Quintessential constraint satisfaction backtracking problem.	LC Top
68	Palindrome Partitioning		Backtracking, DP	Partitioning a string into palindromic substrings.	LC Top, NeetCode

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💻 Dynamic Programming (1D)

#	Problem	Difficulty	Concepts	Why MAANG+ Loves It	Source Hint*
69	⭐ Climbing Stairs		DP (Fibonacci)	The introductory DP problem, equivalent to Fibonacci sequence.	LC Top, Blind 75
70	⭐ Coin Change		DP (Unbounded Knapsack)	Classic DP problem for minimum coins. Tests state definition and transitions.	LC Top, Blind 75
71	⭐ Longest Increasing Subsequence		DP, Binary Search	Fundamental subsequence problem. Can be optimized with Binary Search (patience sorting).	LC Top, Blind 75
72	⭐ Word Break		DP, String	Checking if a string can be segmented using a dictionary. Common string DP.	LC Top, Blind 75
73	⭐ House Robber		DP	Simple 1D DP with non-adjacent constraint.	LC Top, Blind 75
74	House Robber II		DP	Variation of House Robber with circular arrangement. Tests reducing to subproblems.	LC Top, Blind 75
75	Decode Ways		DP, String	Counting ways to decode a numeric string. Tests handling DP states carefully.	LC Top, Blind 75
76	Maximum Product Subarray		DP	(Re-listed) Requires tracking both max and min product ending at index i.	LC Top, Blind 75
77	Partition Equal Subset Sum		DP (0/1 Knapsack)	Subset sum variation. Tests boolean DP state.	LC Top, NeetCode

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🧱 Dynamic Programming (2D & Advanced)

#	Problem	Difficulty	Concepts	Why MAANG+ Loves It	Source Hint*
78	Unique Paths		DP (Grid)	Basic 2D DP on a grid. Calculating paths from top-left to bottom-right.	LC Top, Blind 75
79	Longest Common Subsequence		DP (2D String)	Fundamental DP problem for comparing two sequences.	LC Top, Blind 75
80	Edit Distance		DP (2D String)	Classic DP for string transformation distance (Levenshtein).	LC Top, NeetCode
81	Best Time to Buy and Sell Stock with Cooldown		DP (State Machine)	Stock problem variation requiring state machine DP (buy, sell, cooldown).	LC Top, NeetCode
82	Regular Expression Matching		DP, Recursion	Complex DP involving matching patterns with '.' and '*'. Tests careful state transitions.	LC Top
83	Burst Balloons		DP (Interval)	Challenging interval DP. Requires thinking about the last operation.	LC Top, NeetCode
84	Maximal Square		DP (Grid)	Finding the largest square of 1s in a binary matrix. Common 2D DP pattern.	LC Top

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🌐 Graph (BFS/DFS/Union-Find)

#	Problem	Difficulty	Concepts	Why MAANG+ Loves It	Source Hint*
85	⭐ Number of Islands		BFS/DFS, Grid	The fundamental graph traversal problem on a grid. Counts connected components.	LC Top, Blind 75
86	⭐ Clone Graph		BFS/DFS, Hashing	Deep copying graph structure. Tests handling visited nodes and recursion/iteration.	LC Top, Blind 75
87	Pacific Atlantic Water Flow		BFS/DFS, Grid	Multi-source traversal from oceans inward. Tests simultaneous graph traversals.	LC Top, Blind 75
88	⭐ Course Schedule		Topological Sort (DFS/BFS)	Detecting cycles in a directed graph (prerequisite check). Essential pattern.	LC Top, Blind 75
89	Course Schedule II		Topological Sort	Finding a valid course order (if one exists). Extends Course Schedule I.	LC Top, NeetCode
90	Number of Connected Components in an Undirected Graph (Premium)		Union-Find, BFS/DFS	Basic connectivity check, solvable efficiently with Union-Find.	Blind 75, NeetCode
91	Graph Valid Tree (Premium)		Union-Find, BFS/DFS	Checking if a graph is a tree (connected and acyclic). Combines concepts.	Blind 75, NeetCode
92	Redundant Connection		Union-Find	Finding the edge that creates a cycle in an undirected graph. Classic Union-Find.	NeetCode

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🗺️ Graph (Advanced & Shortest Path)

#	Problem	Difficulty	Concepts	Why MAANG+ Loves It	Source Hint*
93	⭐ Word Ladder		BFS, Implicit Graph	Shortest path on an implicit graph where nodes are words and edges are transformations.	LC Top, Blind 75
94	Network Delay Time		Dijkstra's/Bellman-Ford, BFS	Shortest path from a source in a weighted directed graph (non-negative weights).	LC Top, NeetCode
95	Cheapest Flights Within K Stops		Bellman-Ford / Modified Dijkstra	Shortest path with constraint on number of edges. Tests modified algorithms.	NeetCode
96	Alien Dictionary (Premium)		Topological Sort, Graph Building	Deriving character order from a sorted list of words. Complex graph construction.	Blind 75, NeetCode
97	Critical Connections in a Network		Tarjan's Algorithm (Bridges)	Finding bridges in a graph. Tests understanding of advanced graph algorithms.	NeetCode

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🔍 Binary Search

(Problems like Find Minimum in Rotated Sorted Array, Search in Rotated Sorted Array are already listed)

#	Problem	Difficulty	Concepts	Why MAANG+ Loves It	Source Hint*
98	⭐ Binary Search		Binary Search	The core algorithm itself. Essential foundation.	LC Top
99	Search a 2D Matrix		Binary Search	Applying binary search on a conceptually flattened sorted 2D matrix.	LC Top, Blind 75
100	Time Based Key-Value Store		Hashing, Binary Search	Searching for a value based on timestamp. Requires binary search on timestamps.	LC Top, Blind 75
101	⭐ Median of Two Sorted Arrays		Binary Search	Advanced binary search on partitions to find the median efficiently.	LC Top, Blind 75
102	Koko Eating Bananas		Binary Search on Answer	Searching for the minimum speed (the answer) within a possible range.	NeetCode

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💡 Greedy

#	Problem	Difficulty	Concepts	Why MAANG+ Loves It	Source Hint*
103	⭐ Maximum Subarray		Greedy (Kadane's)	(Re-listed) Can be solved optimally with a simple greedy approach (Kadane's).	LC Top, Blind 75
104	Jump Game		Greedy	Checking reachability by tracking the maximum reachable index greedily.	LC Top, Blind 75
105	Jump Game II		Greedy, BFS	Finding the minimum jumps. Can be solved greedily or viewed as a BFS level order.	LC Top, NeetCode
106	Gas Station		Greedy	Classic greedy problem proving existence and finding a valid starting point.	LC Top, NeetCode
107	Hand of Straights		Greedy, Hashing	Forming consecutive groups greedily using counts.	NeetCode
108	Merge Triplets to Form Target Triplet		Greedy	Simple greedy check if the target triplet can be formed by valid merges.	NeetCode
109	Partition Labels		Greedy, Two Pointers	Finding the smallest partitions such that each letter appears in at most one part.	LC Top, NeetCode

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📐 Math & Bit Manipulation

#	Problem	Difficulty	Concepts	Why MAANG+ Loves It	Source Hint*
110	Number of 1 Bits		Bit Manipulation	Basic bit counting (Hamming weight).	LC Top, Blind 75
111	Counting Bits		Bit Manipulation, DP	Calculating bits for numbers 0 to n efficiently, often using DP relation.	LC Top, Blind 75
112	Reverse Bits		Bit Manipulation	Reversing the bits of an integer. Tests careful bit shifting and masking.	LC Top, Blind 75
113	Missing Number		Bit Manipulation (XOR), Math	Finding the missing number in a range using XOR properties or sum formula.	LC Top, Blind 75
114	⭐ Sum of Two Integers		Bit Manipulation	Adding numbers without using + or -. Tests understanding of bitwise addition.	LC Top, Blind 75
115	Reverse Integer		Math, Overflow Check	Reversing digits of an integer while handling potential overflow.	LC Top
116	Pow(x, n)		Recursion, Math	Efficient exponentiation using recursion (exponentiation by squaring).	LC Top
117	Rotate Image		Math, Matrix	Rotating a matrix in-place. Tests index manipulation and layer-by-layer approach.	LC Top, NeetCode
118	Spiral Matrix		Matrix Traversal	Traversing a matrix in a spiral pattern. Tests boundary and direction handling.	LC Top, NeetCode
119	Set Matrix Zeroes		Matrix, Space Optimization	Setting rows/columns to zero efficiently, often using O(1) extra space.	LC Top, NeetCode

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🧩 Intervals

#	Problem	Difficulty	Concepts	Why MAANG+ Loves It	Source Hint*
120	⭐ Insert Interval		Interval Merging	Inserting a new interval into sorted, non-overlapping intervals and merging.	LC Top, Blind 75
121	⭐ Merge Intervals		Sorting, Intervals	The canonical interval merging problem after sorting by start time.	LC Top, Blind 75
122	⭐ Non-overlapping Intervals		Greedy, Sorting	Finding minimum removals to make intervals non-overlapping. Classic greedy choice.	LC Top, Blind 75
123	Meeting Rooms (Premium)		Sorting, Intervals	Checking if a person can attend all meetings (no overlaps). Basic interval check.	Blind 75, NeetCode
124	⭐ Meeting Rooms II (Premium)		Heap, Sorting	Finding the minimum number of rooms required. Tests heap or sweep-line logic.	Blind 75, NeetCode
125	Minimum Interval to Include Each Query		Heap, Sorting, Sweep Line	Advanced interval problem requiring efficient querying using heaps and sorting.	NeetCode

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🚀 Final Thoughts & Next Steps

This list covers a broad spectrum of DSA patterns essential for MAANG+ interviews.

1. Understand the Core Concept: Don't just memorize solutions. Understand why a particular approach works (e.g., why use a heap for Kth largest? Why is Kadane's greedy?).
2. Practice Variations: Once you solve a problem, think about variations (e.g., different constraints, follow-up questions).
3. Time Yourself: Simulate interview conditions. Can you solve medium problems within 20-30 minutes?
4. Explain Your Thought Process: Practice articulating your solution clearly, step-by-step. This is crucial in interviews.
5. Review Regularly: Spaced repetition helps solidify concepts.

Good luck with your preparation! You've got this! 🌟

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