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Amazon DSA Interview Questions

1957 curated coding interview questions directly asked in Amazon technical rounds, sorted by frequency with recency and difficulty diagnostics.

⚡ Open Interactive Tracker (1957 Problems) 🔥 Must-Solve Problem Pool 🏢 All Companies Directory

1957 Total Questions

524 (27%) Easy Problems

1075 (55%) Medium Problems

358 (18%) Hard Problems

🔥 Most Tested Topics:

Arrays (761)Core DSA (658)Strings (303)Trees (222)Graphs (64)

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Showing top 200 of 1957 questions. View all 1957 in the interactive tracker.

Showing 200 of 200 displayed

ID	Problem	Difficulty	Topic	Pattern	Acceptance	Frequency	Recency
1	Two Sum	Easy	Arrays	Sorting / Prefix / Scan; Two Pointers	57.5%	100.0%	30d
42	Trapping Rain Water	Hard	Core DSA	Two Pointers	67.4%	87.5%	30d
3	Longest Substring Without Repeating Characters	Medium	Strings; Trees	Hashing / Sliding Window; DFS / BFS; Sliding Window	39.1%	75.0%	30d
200	Number of Islands	Medium	Graphs	BFS / DFS / Topological Sort	64.4%	75.0%	30d
207	Course Schedule	Medium	Graphs	BFS / DFS / Topological Sort	51.4%	75.0%	30d
994	Rotting Oranges	Medium	Core DSA	Implementation / Reasoning	58.7%	75.0%	30d
15	3Sum	Medium	Arrays	Sorting / Prefix / Scan	39.1%	75.0%	30d
3914	Minimum Operations to Make Array Non Decreasing	Medium	Arrays	Sorting / Prefix / Scan	55.0%	75.0%	30d
5	Longest Palindromic Substring	Medium	Strings; Trees	Hashing / Sliding Window; DFS / BFS	37.8%	75.0%	30d
121	Best Time to Buy and Sell Stock	Easy	Core DSA	Implementation / Reasoning	56.8%	62.5%	30d
146	LRU Cache	Medium	Design	Data Structure Design	47.4%	62.5%	30d
875	Koko Eating Bananas	Medium	Binary Search	Binary Search	50.0%	62.5%	30d
2	Add Two Numbers	Medium	Core DSA	Implementation / Reasoning	48.5%	62.5%	30d
253	Meeting Rooms II	Medium	Greedy	Greedy	52.7%	62.5%	30d
347	Top K Frequent Elements	Medium	Heap	Priority Queue	66.4%	62.5%	30d
33	Search in Rotated Sorted Array	Medium	Arrays; Binary Search	Sorting / Prefix / Scan; Binary Search	44.9%	62.5%	30d
4	Median of Two Sorted Arrays	Hard	Arrays; Heap	Sorting / Prefix / Scan; Priority Queue	46.6%	62.5%	30d
75	Sort Colors	Medium	Arrays	Sorting / Prefix / Scan	69.6%	62.5%	30d
424	Longest Repeating Character Replacement	Medium	Strings	Hashing / Sliding Window	59.7%	62.5%	30d
124	Binary Tree Maximum Path Sum	Hard	Arrays; Trees	Sorting / Prefix / Scan; DFS / BFS	42.3%	62.5%	30d
34	Find First and Last Position of Element in Sorted Array	Medium	Arrays	Sorting / Prefix / Scan	48.9%	62.5%	30d
396	Rotate Function	Medium	Arrays	Sorting / Prefix / Scan	54.1%	62.5%	30d
907	Sum of Subarray Minimums	Medium	Arrays	Sorting / Prefix / Scan	38.6%	62.5%	30d
796	Rotate String	Easy	Arrays; Strings	Sorting / Prefix / Scan; Hashing / Sliding Window	66.6%	62.5%	30d
48	Rotate Image	Medium	Arrays	Sorting / Prefix / Scan	80.1%	62.5%	30d
62	Unique Paths	Medium	Core DSA	Implementation / Reasoning	66.8%	62.5%	30d
153	Find Minimum in Rotated Sorted Array	Medium	Arrays; Binary Search	Sorting / Prefix / Scan; Binary Search	54.7%	62.5%	30d
735	Asteroid Collision	Medium	Core DSA	Implementation / Reasoning	47.9%	62.5%	30d
14	Longest Common Prefix	Easy	Core DSA	Implementation / Reasoning	47.6%	62.5%	3m
17	Letter Combinations of a Phone Number	Medium	Strings; Backtracking	Hashing / Sliding Window; Backtracking	66.1%	62.5%	3m
18	4Sum	Medium	Arrays	Sorting / Prefix / Scan	40.6%	62.5%	3m
236	Lowest Common Ancestor of a Binary Tree	Medium	Trees	DFS / BFS	69.3%	62.5%	3m
28	Find the Index of the First Occurrence in a String	Easy	Strings	Hashing / Sliding Window	46.7%	62.5%	3m
31	Next Permutation	Medium	Backtracking	Backtracking	45.3%	62.5%	3m
56	Merge Intervals	Medium	Arrays	Sorting / Prefix / Scan	51.8%	50.0%	30d
70	Climbing Stairs	Easy	Dynamic Programming	State Transition	54.1%	50.0%	30d
23	Merge k Sorted Lists	Hard	Arrays; Linked List; Heap	Sorting / Prefix / Scan; Two Pointers; Priority Queue	59.6%	50.0%	30d
26	Remove Duplicates from Sorted Array	Easy	Arrays	Sorting / Prefix / Scan; Two Pointers	62.8%	50.0%	30d
138	Copy List with Random Pointer	Medium	Linked List	Two Pointers	62.9%	50.0%	30d
198	House Robber	Medium	Dynamic Programming	State Transition	53.2%	50.0%	30d
169	Majority Element	Easy	Core DSA	Implementation / Reasoning	66.3%	50.0%	30d
9	Palindrome Number	Easy	Strings	Hashing / Sliding Window	60.6%	50.0%	30d
210	Course Schedule II	Medium	Graphs	BFS / DFS / Topological Sort	55.5%	50.0%	30d
152	Maximum Product Subarray	Medium	Arrays	Sorting / Prefix / Scan	36.4%	50.0%	30d
76	Minimum Window Substring	Hard	Arrays; Strings; Trees	Sorting / Prefix / Scan; Hashing / Sliding Window; DFS / BFS; Sliding Window	47.5%	50.0%	30d
3920	Maximize Fixed Points After Deletions	Hard	Core DSA	Implementation / Reasoning	18.9%	50.0%	30d
295	Find Median from Data Stream	Hard	Heap	Priority Queue	54.5%	50.0%	30d
2661	First Completely Painted Row or Column	Medium	Core DSA	Implementation / Reasoning	63.9%	50.0%	30d
1674	Minimum Moves to Make Array Complementary	Medium	Arrays	Sorting / Prefix / Scan	65.0%	50.0%	30d
19	Remove Nth Node From End of List	Medium	Trees; Linked List	DFS / BFS; Two Pointers	51.6%	50.0%	30d
21	Merge Two Sorted Lists	Easy	Arrays; Linked List	Sorting / Prefix / Scan; Two Pointers	68.3%	50.0%	3m
45	Jump Game II	Medium	Greedy	Greedy	42.9%	50.0%	3m
136	Single Number	Easy	Core DSA	Implementation / Reasoning	77.7%	50.0%	3m
238	Product of Array Except Self	Medium	Arrays	Sorting / Prefix / Scan	68.9%	50.0%	3m
239	Sliding Window Maximum	Hard	Arrays	Sorting / Prefix / Scan; Sliding Window	48.8%	50.0%	3m
739	Daily Temperatures	Medium	Stack / Queue	Monotonic Stack / Simulation	68.7%	50.0%	3m
1757	Recyclable and Low Fat Products	Easy	Arrays	Sorting / Prefix / Scan	88.6%	50.0%	3m
287	Find the Duplicate Number	Medium	Arrays	Sorting / Prefix / Scan	64.3%	50.0%	3m
6	Zigzag Conversion	Medium	Core DSA	Implementation / Reasoning	54.2%	50.0%	3m
981	Time Based Key-Value Store	Medium	Core DSA	Implementation / Reasoning	49.9%	50.0%	3m
155	Min Stack	Medium	Stack / Queue	Monotonic Stack / Simulation	58.2%	50.0%	3m
27	Remove Element	Easy	Core DSA	Implementation / Reasoning	61.8%	50.0%	3m
485	Max Consecutive Ones	Easy	Core DSA	Implementation / Reasoning	65.2%	50.0%	3m
143	Reorder List	Medium	Linked List	Two Pointers	65.3%	50.0%	3m
852	Peak Index in a Mountain Array	Medium	Arrays; Binary Search	Sorting / Prefix / Scan; Binary Search	66.8%	50.0%	3m
234	Palindrome Linked List	Easy	Strings; Linked List	Hashing / Sliding Window; Two Pointers	58.0%	50.0%	3m
199	Binary Tree Right Side View	Medium	Trees	DFS / BFS	70.2%	50.0%	3m
55	Jump Game	Medium	Greedy	Greedy	40.9%	50.0%	3m
176	Second Highest Salary	Medium	Core DSA	Implementation / Reasoning	47.0%	50.0%	3m
322	Coin Change	Medium	Dynamic Programming	State Transition	48.4%	50.0%	3m
349	Intersection of Two Arrays	Easy	Arrays	Sorting / Prefix / Scan	77.8%	50.0%	3m
135	Candy	Hard	Core DSA	Implementation / Reasoning	48.5%	50.0%	6m
202	Happy Number	Easy	Core DSA	Implementation / Reasoning	59.7%	50.0%	6m
110	Balanced Binary Tree	Easy	Trees	DFS / BFS	58.4%	50.0%	6m
3010	Divide an Array Into Subarrays With Minimum Cost I	Easy	Arrays	Sorting / Prefix / Scan	80.6%	50.0%	6m
230	Kth Smallest Element in a BST	Medium	Trees; Heap	DFS / BFS; Priority Queue	76.8%	50.0%	all
973	K Closest Points to Origin	Medium	Core DSA	Implementation / Reasoning	69.0%	50.0%	all
1492	The kth Factor of n	Medium	Heap	Priority Queue	70.4%	50.0%	all
2055	Plates Between Candles	Medium	Core DSA	Implementation / Reasoning	47.5%	50.0%	all
2214	Minimum Health to Beat Game	Medium	Arrays	Sorting / Prefix / Scan	58.8%	50.0%	all
560	Subarray Sum Equals K	Medium	Arrays	Sorting / Prefix / Scan	47.3%	37.5%	30d
49	Group Anagrams	Medium	Strings	Hashing / Sliding Window	72.6%	37.5%	30d
11	Container With Most Water	Medium	Core DSA	Two Pointers	60.0%	37.5%	30d
20	Valid Parentheses	Easy	Strings	Hashing / Sliding Window	44.2%	37.5%	30d
53	Maximum Subarray	Medium	Arrays	Sorting / Prefix / Scan	53.3%	37.5%	30d
35	Search Insert Position	Easy	Binary Search	Binary Search	51.3%	37.5%	30d
496	Next Greater Element I	Easy	Stack / Queue	Monotonic Stack / Simulation	76.1%	37.5%	30d
394	Decode String	Medium	Strings; Dynamic Programming; Stack / Queue	Hashing / Sliding Window; State Transition; Monotonic Stack / Simulation	62.6%	37.5%	30d
128	Longest Consecutive Sequence	Medium	Core DSA	Implementation / Reasoning	47.1%	37.5%	30d
273	Integer to English Words	Hard	Strings	Hashing / Sliding Window	35.0%	37.5%	30d
1559	Detect Cycles in 2D Grid	Medium	Linked List	Two Pointers	63.3%	37.5%	30d
1268	Search Suggestions System	Medium	Binary Search	Binary Search	65.2%	37.5%	30d
1004	Max Consecutive Ones III	Medium	Core DSA	Implementation / Reasoning	67.7%	37.5%	30d
215	Kth Largest Element in an Array	Medium	Arrays; Heap	Sorting / Prefix / Scan; Priority Queue	68.9%	37.5%	30d
278	First Bad Version	Easy	Core DSA	Implementation / Reasoning	47.1%	37.5%	30d
2385	Amount of Time for Binary Tree to Be Infected	Medium	Trees	DFS / BFS	65.4%	37.5%	30d
84	Largest Rectangle in Histogram	Hard	Core DSA	Implementation / Reasoning	49.9%	37.5%	30d
416	Partition Equal Subset Sum	Medium	Arrays; Dynamic Programming	Sorting / Prefix / Scan; State Transition	49.5%	37.5%	30d
174	Dungeon Game	Hard	Core DSA	Implementation / Reasoning	41.4%	37.5%	30d
1011	Capacity To Ship Packages Within D Days	Medium	Binary Search	Binary Search	73.9%	37.5%	30d
102	Binary Tree Level Order Traversal	Medium	Trees	DFS / BFS	72.7%	37.5%	30d
3660	Jump Game IX	Medium	Greedy	Greedy	46.2%	37.5%	30d
387	First Unique Character in a String	Easy	Strings	Hashing / Sliding Window	65.5%	37.5%	30d
3629	Minimum Jumps to Reach End via Prime Teleportation	Medium	Arrays; Greedy	Sorting / Prefix / Scan; Greedy	44.8%	37.5%	30d
300	Longest Increasing Subsequence	Medium	Dynamic Programming	State Transition	59.4%	37.5%	30d
658	Find K Closest Elements	Medium	Core DSA	Implementation / Reasoning	49.7%	37.5%	30d
704	Binary Search	Easy	Binary Search	Binary Search	60.9%	37.5%	30d
100	Same Tree	Easy	Trees	DFS / BFS	67.1%	37.5%	30d
142	Linked List Cycle II	Medium	Linked List	Two Pointers	57.9%	37.5%	30d
788	Rotated Digits	Medium	Arrays; Binary Search	Sorting / Prefix / Scan; Binary Search	64.0%	37.5%	30d
1934	Confirmation Rate	Medium	Core DSA	Implementation / Reasoning	62.0%	37.5%	30d
7	Reverse Integer	Medium	Core DSA	Implementation / Reasoning	31.9%	37.5%	30d
3928	Minimum Cost to Buy Apples II	Hard	Arrays	Sorting / Prefix / Scan	31.4%	37.5%	30d
67	Add Binary	Easy	Core DSA	Implementation / Reasoning	58.1%	37.5%	30d
85	Maximal Rectangle	Hard	Core DSA	Implementation / Reasoning	58.8%	37.5%	30d
1665	Minimum Initial Energy to Finish Tasks	Hard	Arrays	Sorting / Prefix / Scan	76.4%	37.5%	30d
3462	Maximum Sum With at Most K Elements	Medium	Arrays	Sorting / Prefix / Scan	60.8%	37.5%	30d
232	Implement Queue using Stacks	Easy	Stack / Queue	Monotonic Stack / Simulation	69.8%	37.5%	30d
863	All Nodes Distance K in Binary Tree	Medium	Trees	DFS / BFS	67.7%	37.5%	30d
69	Sqrt(x)	Easy	Binary Search	Binary Search	41.8%	37.5%	30d
1691	Maximum Height by Stacking Cuboids	Hard	Arrays; Stack / Queue	Sorting / Prefix / Scan; Monotonic Stack / Simulation	62.0%	37.5%	30d
283	Move Zeroes	Easy	Core DSA	Two Pointers	63.8%	37.5%	30d
22	Generate Parentheses	Medium	Strings	Hashing / Sliding Window	78.7%	37.5%	30d
3752	Lexicographically Smallest Negated Permutation that Sums to Target	Medium	Arrays; Graphs; Backtracking	Sorting / Prefix / Scan; BFS / DFS / Topological Sort; Backtracking	31.2%	37.5%	30d
621	Task Scheduler	Medium	Greedy	Greedy	63.1%	37.5%	30d
217	Contains Duplicate	Easy	Arrays	Sorting / Prefix / Scan	64.4%	37.5%	30d
1929	Concatenation of Array	Easy	Arrays	Sorting / Prefix / Scan	90.3%	37.5%	30d
242	Valid Anagram	Easy	Strings	Hashing / Sliding Window	68.1%	37.5%	30d
2272	Substring With Largest Variance	Hard	Strings; Trees	Hashing / Sliding Window; DFS / BFS	46.0%	37.5%	30d
3043	Find the Length of the Longest Common Prefix	Medium	Core DSA	Implementation / Reasoning	62.2%	37.5%	30d
137	Single Number II	Medium	Core DSA	Implementation / Reasoning	67.1%	37.5%	30d
74	Search a 2D Matrix	Medium	Arrays; Binary Search	Sorting / Prefix / Scan; Binary Search	53.9%	37.5%	30d
767	Reorganize String	Medium	Strings	Hashing / Sliding Window	57.1%	37.5%	30d
78	Subsets	Medium	Backtracking	Backtracking	82.3%	37.5%	30d
1494	Parallel Courses II	Hard	Graphs	BFS / DFS / Topological Sort	31.0%	37.5%	30d
733	Flood Fill	Easy	Core DSA	Implementation / Reasoning	68.3%	37.5%	30d
36	Valid Sudoku	Medium	Strings; Backtracking	Hashing / Sliding Window; Backtracking	64.5%	37.5%	3m
54	Spiral Matrix	Medium	Arrays	Sorting / Prefix / Scan	56.8%	37.5%	3m
79	Word Search	Medium	Strings; Binary Search	Hashing / Sliding Window; Binary Search	47.4%	37.5%	3m
88	Merge Sorted Array	Easy	Arrays	Sorting / Prefix / Scan	54.9%	37.5%	3m
118	Pascal's Triangle	Easy	Core DSA	Implementation / Reasoning	78.9%	37.5%	3m
297	Serialize and Deserialize Binary Tree	Hard	Trees; Design	DFS / BFS; Data Structure Design	60.8%	37.5%	3m
162	Find Peak Element	Medium	Binary Search	Binary Search	47.0%	37.5%	3m
41	First Missing Positive	Hard	Arrays	Sorting / Prefix / Scan	42.9%	37.5%	3m
51	N-Queens	Hard	Backtracking	Backtracking	75.5%	37.5%	3m
61	Rotate List	Medium	Arrays; Linked List	Sorting / Prefix / Scan; Two Pointers	42.6%	37.5%	3m
540	Single Element in a Sorted Array	Medium	Arrays	Sorting / Prefix / Scan	59.3%	37.5%	3m
179	Largest Number	Medium	Core DSA	Implementation / Reasoning	43.1%	37.5%	3m
904	Fruit Into Baskets	Medium	Core DSA	Implementation / Reasoning	51.1%	37.5%	3m
134	Gas Station	Medium	Greedy	Greedy	48.0%	37.5%	3m
509	Fibonacci Number	Easy	Core DSA	Implementation / Reasoning	74.1%	37.5%	3m
567	Permutation in String	Medium	Strings; Backtracking	Hashing / Sliding Window; Sliding Window; Backtracking	48.9%	37.5%	3m
175	Combine Two Tables	Easy	Core DSA	Implementation / Reasoning	79.5%	37.5%	3m
344	Reverse String	Easy	Strings	Hashing / Sliding Window	80.8%	37.5%	3m
2910	Minimum Number of Groups to Create a Valid Assignment	Medium	Arrays; Strings	Sorting / Prefix / Scan; Hashing / Sliding Window	25.3%	37.5%	3m
16	3Sum Closest	Medium	Arrays	Sorting / Prefix / Scan	48.6%	37.5%	3m
1648	Sell Diminishing-Valued Colored Balls	Medium	Core DSA	Implementation / Reasoning	30.2%	37.5%	3m
547	Number of Provinces	Medium	Core DSA	Implementation / Reasoning	70.4%	37.5%	3m
987	Vertical Order Traversal of a Binary Tree	Hard	Trees	DFS / BFS	53.8%	37.5%	3m
46	Permutations	Medium	Backtracking	Backtracking	81.9%	37.5%	3m
58	Length of Last Word	Easy	Strings	Hashing / Sliding Window	58.8%	37.5%	3m
139	Word Break	Medium	Strings; Dynamic Programming	Hashing / Sliding Window; State Transition	49.5%	37.5%	3m
240	Search a 2D Matrix II	Medium	Arrays; Binary Search	Sorting / Prefix / Scan; Binary Search	57.3%	37.5%	3m
209	Minimum Size Subarray Sum	Medium	Arrays	Sorting / Prefix / Scan	51.7%	37.5%	3m
435	Non-overlapping Intervals	Medium	Arrays; Greedy	Sorting / Prefix / Scan; Greedy	57.1%	37.5%	3m
66	Plus One	Easy	Core DSA	Implementation / Reasoning	50.0%	37.5%	3m
12	Integer to Roman	Medium	Strings	Hashing / Sliding Window	71.0%	37.5%	3m
38	Count and Say	Medium	Core DSA	Implementation / Reasoning	62.9%	37.5%	3m
125	Valid Palindrome	Easy	Strings	Hashing / Sliding Window	53.3%	37.5%	3m
122	Best Time to Buy and Sell Stock II	Medium	Core DSA	Implementation / Reasoning	71.1%	37.5%	3m
8	String to Integer (atoi)	Medium	Strings	Hashing / Sliding Window	21.0%	37.5%	3m
493	Reverse Pairs	Hard	Core DSA	Implementation / Reasoning	34.2%	37.5%	3m
83	Remove Duplicates from Sorted List	Easy	Arrays; Linked List	Sorting / Prefix / Scan; Two Pointers	56.7%	37.5%	3m
224	Basic Calculator	Hard	Stack / Queue	Monotonic Stack / Simulation	46.9%	37.5%	3m
1482	Minimum Number of Days to Make m Bouquets	Medium	Arrays	Sorting / Prefix / Scan	56.6%	37.5%	3m
1539	Kth Missing Positive Number	Easy	Arrays; Heap	Sorting / Prefix / Scan; Priority Queue	63.5%	37.5%	3m
274	H-Index	Medium	Core DSA	Implementation / Reasoning	41.4%	37.5%	3m
43	Multiply Strings	Medium	Strings	Hashing / Sliding Window	44.2%	37.5%	3m
50	Pow(x, n)	Medium	Core DSA	Implementation / Reasoning	38.7%	37.5%	3m
32	Longest Valid Parentheses	Hard	Strings	Hashing / Sliding Window	38.8%	37.5%	3m
528	Random Pick with Weight	Medium	Core DSA	Implementation / Reasoning	49.1%	37.5%	3m
24	Swap Nodes in Pairs	Medium	Trees	DFS / BFS	69.5%	37.5%	3m
456	132 Pattern	Medium	Strings	Hashing / Sliding Window	34.8%	37.5%	3m
680	Valid Palindrome II	Easy	Strings	Hashing / Sliding Window	44.3%	37.5%	3m
443	String Compression	Medium	Strings	Hashing / Sliding Window	60.0%	37.5%	3m
140	Word Break II	Hard	Strings; Dynamic Programming	Hashing / Sliding Window; State Transition	55.6%	37.5%	3m
455	Assign Cookies	Easy	Core DSA	Implementation / Reasoning	55.0%	37.5%	3m
410	Split Array Largest Sum	Hard	Arrays	Sorting / Prefix / Scan	60.4%	37.5%	3m
977	Squares of a Sorted Array	Easy	Arrays	Sorting / Prefix / Scan	73.8%	37.5%	3m
63	Unique Paths II	Medium	Core DSA	Implementation / Reasoning	44.5%	37.5%	3m
86	Partition List	Medium	Dynamic Programming; Linked List	State Transition; Two Pointers	61.2%	37.5%	3m
992	Subarrays with K Different Integers	Hard	Arrays	Sorting / Prefix / Scan	68.1%	37.5%	3m
190	Reverse Bits	Easy	Core DSA	Implementation / Reasoning	68.4%	37.5%	3m
543	Diameter of Binary Tree	Easy	Trees	DFS / BFS	65.5%	37.5%	3m
472	Concatenated Words	Hard	Strings	Hashing / Sliding Window	49.8%	37.5%	3m
460	LFU Cache	Hard	Design	Data Structure Design	49.2%	37.5%	3m
1752	Check if Array Is Sorted and Rotated	Easy	Arrays; Binary Search	Sorting / Prefix / Scan; Binary Search	57.2%	37.5%	3m
380	Insert Delete GetRandom O(1)	Medium	Core DSA	Implementation / Reasoning	55.4%	37.5%	3m
383	Ransom Note	Easy	Core DSA	Implementation / Reasoning	66.0%	37.5%	3m
99	Recover Binary Search Tree	Medium	Trees; Binary Search	DFS / BFS; Binary Search	59.7%	37.5%	3m

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