Top 120 Most Frequently Asked Amazon SDE-1 Interview Questions (2022–2025)
📌 Amazon SDE-1 Interview Preparation (2021–2025)
🧠 Dynamic Programming – Curated DP problems frequently asked in Amazon SDE-1 interviews: https://leetcode.com/discuss/post/7454002/dynamic-programming-problems-for-amazon-f8wqq/
🌳 Trees – High-yield tree problems covering traversal, BSTs, and structural patterns: https://leetcode.com/discuss/post/7454008/unique-tree-related-from-amazon-sde-1-in-nvf6/
🕸️ Graphs – Amazon-focused graph problems on BFS, DFS, shortest paths, and connectivity: https://leetcode.com/discuss/post/7454010/graph-problems-for-amazon-sde-1-intervie-96rq/
📚 Stack & Queue – Interview-relevant stack and queue problems with real patterns: https://leetcode.com/discuss/post/7454020/amazon-sde-1-stack-queue-interview-probl-19m2/
🚀
| Question (LeetCode #) | Link | Difficulty | Topics |
|---|---|---|---|
| Two Sum (1) | leetcode.com/problems/two-sum | Easy | Array, Hash Table |
| Best Time to Buy and Sell Stock I (121) | leetcode.com/problems/best-time-to-buy-and-sell-stock | Easy | Array, Dynamic Programming |
| LRU Cache (146) | leetcode.com/problems/lru-cache | Medium | Design, Hash Table |
| Number of Islands (200) | leetcode.com/problems/number-of-islands | Medium | Graph (DFS/BFS), Grid |
| Reorganize String (767) | leetcode.com/problems/reorganize-string | Medium | Greedy, Heap, String |
| Longest Palindromic Substring (5) | leetcode.com/problems/longest-palindromic-substring | Medium | String, Dynamic Programming |
| Add Two Numbers (2) | leetcode.com/problems/add-two-numbers | Medium | Linked List, Math |
| First and Last Position of Element in Sorted Array (34) | leetcode.com/problems/find-first-and-last-position-of-element-in-sorted-array | Medium | Array, Binary Search |
| Koko Eating Bananas (875) | leetcode.com/problems/koko-eating-bananas | Medium | Binary Search, Greedy |
| Trapping Rain Water (42) | leetcode.com/problems/trapping-rain-water | Hard | Array, Two Pointers, Stack |
| Jump Game II (45) | leetcode.com/problems/jump-game-ii | Medium | Greedy, BFS, Dynamic Programming |
| Group Anagrams (49) | leetcode.com/problems/group-anagrams | Medium | Hash Table, String |
| Longest Substring Without Repeating Characters (3) | leetcode.com/problems/longest-substring-without-repeating-characters | Medium | String, Sliding Window |
| Merge k Sorted Lists (23) | leetcode.com/problems/merge-k-sorted-lists | Hard | Linked List, Heap |
| Candy (135) | leetcode.com/problems/candy | Hard | Greedy, Dynamic Programming |
| House Robber (198) | leetcode.com/problems/house-robber | Medium | Dynamic Programming |
| Reverse Linked List (206) | leetcode.com/problems/reverse-linked-list | Easy | Linked List |
| Top K Frequent Elements (347) | leetcode.com/problems/top-k-frequent-elements | Medium | Heap, Hash Table |
| Median of Two Sorted Arrays (4) | leetcode.com/problems/median-of-two-sorted-arrays | Hard | Array, Divide & Conquer |
| Valid Parentheses (20) | leetcode.com/problems/valid-parentheses | Easy | Stack, String |
| Generate Parentheses (22) | leetcode.com/problems/generate-parentheses | Medium | Backtracking, String |
| Merge Intervals (56) | leetcode.com/problems/merge-intervals | Medium | Array, Sorting |
| Search a 2D Matrix (74) | leetcode.com/problems/search-a-2d-matrix | Medium | Matrix, Binary Search |
| Minimum Window Substring (76) | leetcode.com/problems/minimum-window-substring | Hard | Sliding Window, Hash Table |
| Best Time to Buy and Sell Stock II (122) | leetcode.com/problems/best-time-to-buy-and-sell-stock-ii | Easy | Greedy |
| Min Stack (155) | leetcode.com/problems/min-stack | Easy | Stack, Design |
| Longest Repeating Character Replacement (424) | leetcode.com/problems/longest-repeating-character-replacement | Medium | Sliding Window, String |
| Palindrome Number (9) | leetcode.com/problems/palindrome-number | Easy | Math |
| Next Permutation (31) | leetcode.com/problems/next-permutation | Medium | Array |
| Search in Rotated Sorted Array (33) | leetcode.com/problems/search-in-rotated-sorted-array | Medium | Binary Search |
| Course Schedule II (210) | leetcode.com/problems/course-schedule-ii | Medium | Graph, Topological Sort |
| Basic Calculator (224) | leetcode.com/problems/basic-calculator | Hard | Stack, String |
| Meeting Rooms II (253) | leetcode.com/problems/meeting-rooms-ii | Medium | Sorting, Heap |
| Coin Change (322) | leetcode.com/problems/coin-change | Medium | Dynamic Programming |
| Number of Connected Components in an Undirected Graph (323) | leetcode.com/problems/number-of-connected-components-in-an-undirected-graph | Medium | Graph, DFS/BFS |
| LFU Cache (460) | leetcode.com/problems/lfu-cache | Hard | Design, Doubly-Linked List |
| Concatenated Words (472) | leetcode.com/problems/concatenated-words | Hard | Trie, Dynamic Programming |
| Flood Fill (733) | leetcode.com/problems/flood-fill | Easy | DFS, Matrix |
| Rotting Oranges (994) | leetcode.com/problems/rotting-oranges | Medium | BFS, Matrix |
| Using a Robot to Print the Lexicographically Smallest String (1165) | leetcode.com/problems/print-foobar-binary | Hard | String, Simulation |
| String to Integer (atoi) (8) | leetcode.com/problems/string-to-integer-atoi | Easy | String, Implementation |
| Integer to Roman (12) | leetcode.com/problems/integer-to-roman | Medium | Math |
| Roman to Integer (13) | leetcode.com/problems/roman-to-integer | Easy | String |
| 3Sum (15) | leetcode.com/problems/3sum | Medium | Array, Two Pointers |
| Rotate Image (48) | leetcode.com/problems/rotate-image | Medium | Array, Matrix |
| Maximum Subarray (53) | leetcode.com/problems/maximum-subarray | Easy | Array, Dynamic Programming |
| Unique Paths (62) | leetcode.com/problems/unique-paths | Medium | Dynamic Programming |
| Edit Distance (72) | leetcode.com/problems/edit-distance | Hard | Dynamic Programming |
| Word Search (79) | leetcode.com/problems/word-search | Medium | DFS, Backtracking |
| Binary Tree Right Side View (199) | leetcode.com/problems/binary-tree-right-side-view | Medium | Tree, BFS |
| Kth Largest Element in an Array (215) | leetcode.com/problems/kth-largest-element-in-an-array | Medium | Heap, Quickselect |
| Contains Duplicate (217) | leetcode.com/problems/contains-duplicate | Easy | Array, Hash Table |
| Invert Binary Tree (226) | leetcode.com/problems/invert-binary-tree | Easy | Tree, Recursion |
| Lowest Common Ancestor of a Binary Tree (236) | leetcode.com/problems/lowest-common-ancestor-of-a-binary-tree | Medium | Tree, Recursion |
| Product of Array Except Self (238) | leetcode.com/problems/product-of-array-except-self | Medium | Array, Prefix Sum |
| Move Zeroes (283) | leetcode.com/problems/move-zeroes | Easy | Array, Two Pointers |
| First Unique Character in a String (387) | leetcode.com/problems/first-unique-character-in-a-string | Easy | Hash Table, String |
| Fizz Buzz (412) | leetcode.com/problems/fizz-buzz | Easy | Simulation |
| Subarray Sum Equals K (560) | leetcode.com/problems/subarray-sum-equals-k | Medium | Hash Table, Prefix Sum |
| Top K Frequent Words (692) | leetcode.com/problems/top-k-frequent-words | Medium | Heap, Hash Table |
| Analyze User Website Visit Pattern (1152) | leetcode.com/problems/analyze-user-website-visit-pattern | Medium | Hash Table, Sorting |
| Count the Number of Substrings With Dominant Ones (2404) | leetcode.com/problems/count-substrings-with-dominant-ones | Hard | String, Prefix Sum |
| Reverse Nodes in k-Group (25) | leetcode.com/problems/reverse-nodes-in-k-group | Hard | Linked List, Recursion |
| Longest Valid Parentheses (32) | leetcode.com/problems/longest-valid-parentheses | Hard | Stack, Dynamic Programming |
| Valid Sudoku (36) | leetcode.com/problems/valid-sudoku | Medium | Hash Table, Matrix |
| Sudoku Solver (37) | leetcode.com/problems/sudoku-solver | Hard | Backtracking |
| Combination Sum (39) | leetcode.com/problems/combination-sum | Medium | Backtracking |
| N-Queens (51) | leetcode.com/problems/n-queens | Hard | Backtracking |
| Jump Game (55) | leetcode.com/problems/jump-game | Medium | Greedy |
| Climbing Stairs (70) | leetcode.com/problems/climbing-stairs | Easy | Dynamic Programming |
| Merge Sorted Array (88) | leetcode.com/problems/merge-sorted-array | Easy | Array |
| Decode Ways (91) | leetcode.com/problems/decode-ways | Medium | Dynamic Programming |
| Validate Binary Search Tree (98) | leetcode.com/problems/validate-binary-search-tree | Medium | Tree, Recursion |
| Word Ladder (127) | leetcode.com/problems/word-ladder | Hard | BFS, String |
| Reorder List (143) | leetcode.com/problems/reorder-list | Medium | Linked List, Two Pointers |
| Evaluate Reverse Polish Notation (150) | leetcode.com/problems/evaluate-reverse-polish-notation | Medium | Stack |
| Find Minimum in Rotated Sorted Array (153) | leetcode.com/problems/find-minimum-in-rotated-sorted-array | Medium | Binary Search |
| Majority Element (169) | leetcode.com/problems/majority-element | Easy | Array, Bit Manipulation |
| Course Schedule I (207) | leetcode.com/problems/course-schedule | Medium | Graph, Topological Sort |
| Word Search II (212) | leetcode.com/problems/word-search-ii | Hard | Trie, Backtracking |
| Sliding Window Maximum (239) | leetcode.com/problems/sliding-window-maximum | Hard | Deque, Heap |
| Valid Anagram (242) | leetcode.com/problems/valid-anagram | Easy | Hash Table, String |
| Missing Number (268) | leetcode.com/problems/missing-number | Easy | Bit Manipulation, Array |
| Alien Dictionary (269) | leetcode.com/problems/alien-dictionary | Hard | Graph, Topological Sort |
| Integer to English Words (273) | leetcode.com/problems/integer-to-english-words | Hard | Math, String |
| Find the Duplicate Number (287) | leetcode.com/problems/find-the-duplicate-number | Medium | Array, Two Pointers |
| Design Tic-Tac-Toe (348) | leetcode.com/problems/design-tic-tac-toe | Medium | Design, Data Structures |
| Insert Delete GetRandom O(1) (380) | leetcode.com/problems/insert-delete-getrandom-o1 | Medium | Design, Hash Table |
| Pacific Atlantic Water Flow (417) | leetcode.com/problems/pacific-atlantic-water-flow | Medium | DFS, Matrix |
| String Compression (443) | leetcode.com/problems/string-compression | Medium | String |
| Number of Provinces (547) | leetcode.com/problems/number-of-provinces | Medium | Graph, BFS/DFS |
| Basic Calculator III (772) | leetcode.com/problems/basic-calculator-iii | Hard | String, Stack |
| Maximize Distance to Closest Person (849) | leetcode.com/problems/maximize-distance-to-closest-person | Medium | Array, Two Pointers |
| Middle of the Linked List (876) | leetcode.com/problems/middle-of-the-linked-list | Easy | Linked List |
| Capacity To Ship Packages Within D Days (1011) | leetcode.com/problems/capacity-to-ship-packages-within-d-days | Medium | Binary Search |
| Lexicographically Smallest Equivalent String (1061) | leetcode.com/problems/lexicographically-smallest-equivalent-string | Hard | Union-Find, Graph |
| Maximum Profit in Job Scheduling (1235) | leetcode.com/problems/maximum-profit-in-job-scheduling | Hard | Dynamic Programming |
| Max Difference You Can Get From Changing an Integer (1932) | leetcode.com/problems/max-difference-you-can-get-from-changing-an-integer | Hard | Math |
| Additional Common Problems (not listed above): | |||
| Max Area of Island (695) | leetcode.com/problems/max-area-of-island | Medium | DFS, Grid |
| K Closest Points to Origin (973) | leetcode.com/problems/k-closest-points-to-origin | Medium | Heap, Sorting |
| Zigzag Level Order Traversal of Binary Tree (103) | leetcode.com/problems/binary-tree-zigzag-level-order-traversal | Medium | Tree, BFS |
| Design Skiplist (1206) | leetcode.com/problems/design-skiplist | Hard | Design, Linked List |
| Serialize and Deserialize Binary Tree (297) | leetcode.com/problems/serialize-and-deserialize-binary-tree | Hard | Tree, Design |
| Find Minimum in Rotated Sorted Array II (154) | leetcode.com/problems/find-minimum-in-rotated-sorted-array-ii | Hard | Binary Search |
| Maximum Depth of Binary Tree (104) | leetcode.com/problems/maximum-depth-of-binary-tree | Easy | Tree, DFS/BFS |
| Path Sum (112) | leetcode.com/problems/path-sum | Medium | Tree, Recursion |
| Path Sum II (113) | leetcode.com/problems/path-sum-ii | Medium | Tree, DFS |
| Next Greater Element II (503) | leetcode.com/problems/next-greater-element-ii | Medium | Stack |
| Single Number (136) | leetcode.com/problems/single-number | Easy | Bit Manipulation |
| Intersection of Two Linked Lists (160) | leetcode.com/problems/intersection-of-two-linked-lists | Easy | Linked List |
| Binary Tree Maximum Path Sum (124) | leetcode.com/problems/binary-tree-maximum-path-sum | Hard | Tree, DFS |
| Remove K Digits (402) | leetcode.com/problems/remove-k-digits | Medium | Stack, Greedy |
| Keys and Rooms (841) | leetcode.com/problems/keys-and-rooms | Medium | DFS/BFS, Graph |
| Word Break (139) | leetcode.com/problems/word-break | Medium | DP, Trie |
| Sort Colors (75) | leetcode.com/problems/sort-colors | Medium | Two Pointers |
| Spiral Matrix (54) | leetcode.com/problems/spiral-matrix | Medium | Array, Simulation |
| Daily Temperatures | |||
| 🔗 https://leetcode.com/problems/daily-temperatures/ |
Binary Tree Level Order Traversal
🔗 https://leetcode.com/problems/binary-tree-level-order-traversal/
Longest Increasing Subsequence
🔗 https://leetcode.com/problems/longest-increasing-subsequence/
Asteroid Collision
🔗 https://leetcode.com/problems/asteroid-collision/
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