Amazon Coding Interview Questions
295 problems · 38 Easy 238 Medium 19 Hard
✓ Interview Solutions & Breakdown
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Amazon problems
Amazon is the most-covered company in this dataset. The loop is anchored by Leadership Principles, and the coding bar is medium-heavy with emphasis on two pointers, sliding window, and hashing. Verbalize your approach before writing code, and expect follow-ups that tighten the constraints.
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Amazon Interview Loop Structure
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Rounds: Online Assessment (2 coding questions + work style) + 4–5 round onsite loop
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Coding Style: Medium-heavy problems. Two pointers, sliding window, heaps, and hash maps are top priorities.
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System Design: Required for SDE-II and above. High-scale microservices, data storage selection, and asynchronous queuing.
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Behavioral: Amazon 16 Leadership Principles: Customer Obsession, Ownership, Bias for Action, Dive Deep. Bar Raiser round included.
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Pro Tips:
- • Format every behavioral response strictly using the STAR method
- • Verbalize test cases and edge cases explicitly
- • Demonstrate frugal and pragmatic architectural trade-offs
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4-Week Preparation Strategy for Amazon
Action PlanTo maximize your offer probability at Amazon, avoid random LeetCode grinding. Follow this structured 4-week roadmap tailored to Amazon's specific interview loop and evaluation bar:
Week 1: High-Frequency Patterns
Focus on foundational patterns tested heavily at Amazon: Two Pointers, Sliding Window, and Hash Map frequency tracking. Solve 10–12 Easy/Medium questions and establish code muscle memory without syntax lookups.
Week 2: Advanced Graph & Tree Drills
Master BFS, DFS, Topological Sorting, and Priority Queues (Min/Max Heaps). Practice articulating state transitions and recursion stack depth trade-offs under real-time interviewer pressure.
Week 3: Timed Mock Coding & Complexity
Simulate real 45-minute technical screens. Spend 5 minutes clarifying requirements, 10 minutes discussing brute-force vs optimal trade-offs, 20 minutes coding cleanly, and 10 minutes dry-running boundary test cases.
Week 4: System Architecture & Behavioral STAR
Draft 5 distinct STAR method stories (Situation, Task, Action, Result) mapped to Amazon's core principles. Review distributed systems fundamentals: caching tiers, partitioning, rate limiting, and database consistency models.
💡 What Amazon Interviewers Evaluate:
Interviewers score candidates across 4 independent pillars: Algorithmic Optimality (arriving at optimal Big-O), Code Craftsmanship (modular functions, clean naming, zero syntax debt), Communication & Thinking Out Loud (proactive collaboration, asking clarifying questions), and Edge Case Rigor (null checks, integer overflows, duplicate inputs).
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High Frequency at Amazon
Most AskedThese problems appear most frequently in Amazon interviews based on reported data.
Longest Substring Without Repeating Characters Medium
Sliding Window Minimum Window Substring Hard
Sliding Window Two Sum II - Input Array Is Sorted Medium
Two Pointers 3Sum Medium
Two Pointers Container With Most Water Medium
Two Pointers Trapping Rain Water Hard
Two Pointers Valid Palindrome Easy
Two Pointers Binary Search Easy
Binary Search Filter by pattern: Sliding Window (24) Two Pointers (48) Binary Search (31) Prefix Sum (8) Hash Map / Set (11) Stack (20) Queue / BFS (10) Heap / Priority Queue (14) Linked List (24) Trees / DFS (18) Graphs (9) Dynamic Programming (25) Greedy (6) Backtracking (14) Trie (3) Union Find (6) Monotonic Stack (5) Topological Sort (4) Bit Manipulation (5) Intervals (3) Matrix (7)
Sliding Window 24 problems
Two Pointers 48 problems
Binary Search 31 problems
Prefix Sum 8 problems
| Problem | Difficulty | Solution | Link | |
|---|---|---|---|---|
| Subarray Sum Equals K
#Array
#Hash Map
#Prefix Sum | Medium | Solution | ||
| Product of Array Except Self
#Array
#Prefix Product | Medium | Solution | ||
| Range Sum Query - Immutable
#Array
#Design
#Prefix Sum | Easy | Solution | ||
| Find Pivot Index
#Array
#Prefix Sum | Easy | Solution | ||
| Running Sum of 1D Array
#Array
#Prefix Sum | Easy | Solution | ||
| Minimum Average Difference
#Array
#Prefix Sum | Medium | Solution | ||
| Max Chunks To Make Sorted
#Array | Medium | Solution | ||
| Max Chunks To Make Sorted II
#Array | Medium | Solution |
Hash Map / Set 11 problems
| Problem | Difficulty | Solution | Link | |
|---|---|---|---|---|
| Two Sum
#Array
#Hash Map | Easy | Solution | ||
| Group Anagrams
#String
#Hash Map
#Sorting | Medium | Solution | ||
| Top K Frequent Elements
#Array
#Hash Map
#Heap | Medium | Solution | ||
| Valid Anagram
#String
#Hash Map
#Sorting | Easy | Solution | ||
| Longest Consecutive Sequence
#Array
#Hash Set | Medium | Solution | ||
| Contains Duplicate
#Array
#Hash Table
#Sorting | Easy | Solution | ||
| Isomorphic Strings
#Hash Table
#String | Easy | Solution | ||
| LRU Cache
#Hash Table
#Linked List
#Design | Medium | Solution | ||
| 4Sum II
#Array
#Hash Table | Medium | Solution | ||
| Number of Good Pairs
#Array
#Hash Table
#Math | Easy | Solution | ||
| Subarray Sum Divisible by K
#Array
#Hash Table
#Prefix Sum | Medium | Solution |
Stack 20 problems
Queue / BFS 10 problems
| Problem | Difficulty | Solution | Link | |
|---|---|---|---|---|
| Number of Islands
#Array
#DFS
#BFS | Medium | Solution | ||
| Rotting Oranges
#Array
#BFS
#Matrix | Medium | Solution | ||
| Binary Tree Level Order Traversal
#Tree
#BFS | Medium | Solution | ||
| Word Ladder
#Hash Set
#BFS
#String | Hard | Solution | ||
| 01 Matrix
#Array
#BFS
#Matrix | Medium | Solution | ||
| Walls and Gates
#Array
#BFS
#Matrix | Medium | Solution | ||
| Shortest Path in Binary Matrix
#Array
#BFS
#Matrix | Medium | Solution | ||
| Open the Lock
#Array
#Hash Table
#BFS | Medium | Solution | ||
| Minimum Genetic Mutation
#Hash Table
#String
#BFS | Medium | Solution | ||
| Jump Game III
#Array
#DFS
#BFS | Medium | Solution |
Heap / Priority Queue 14 problems
Linked List 24 problems
Trees / DFS 18 problems
Graphs 9 problems
| Problem | Difficulty | Solution | Link | |
|---|---|---|---|---|
| Clone Graph
#Graph
#DFS
#BFS | Medium | Solution | ||
| Pacific Atlantic Water Flow
#Graph
#DFS
#BFS | Medium | Solution | ||
| Number of Connected Components in Undirected Graph
#Graph
#DFS
#Union Find | Medium | Solution | ||
| Minimum Height Trees
#DFS
#BFS
#Graph | Medium | Solution | ||
| Network Delay Time
#DFS
#BFS
#Graph | Medium | Solution | ||
| Find Eventual Safe States
#DFS
#BFS
#Graph | Medium | Solution | ||
| All Paths From Source to Target
#Backtracking
#DFS
#BFS | Medium | Solution | ||
| Cheapest Flights Within K Stops
#Dynamic Programming
#DFS
#BFS | Medium | Solution | ||
| Graph Valid Tree
#Depth-First Search
#Breadth-First Search
#Union Find | Medium | Solution |
Dynamic Programming 25 problems
| Problem | Difficulty | Solution | Link | |
|---|---|---|---|---|
| Climbing Stairs
#DP
#Math
#Memoization | Easy | Solution | ||
| House Robber
#Array
#DP | Medium | Solution | ||
| Coin Change
#Array
#DP
#BFS | Medium | Solution | ||
| Longest Increasing Subsequence
#Array
#DP
#Binary Search | Medium | Solution | ||
| Longest Common Subsequence
#String
#DP | Medium | Solution | ||
| Word Break
#String
#DP
#Hash Set | Medium | Solution | ||
| Edit Distance
#String
#DP | Hard | Solution | ||
| Unique Paths
#Math
#DP
#Combinatorics | Medium | Solution | ||
| Maximum Subarray
#Array
#DP
#Divide and Conquer | Medium | Solution | ||
| Decode Ways
#String
#DP | Medium | Solution | ||
| Min Cost Climbing Stairs
#Array
#Dynamic Programming | Easy | Solution | ||
| House Robber II
#Array
#Dynamic Programming | Medium | Solution | ||
| Partition Equal Subset Sum
#Array
#Dynamic Programming | Medium | Solution | ||
| Target Sum
#Array
#Dynamic Programming
#Backtracking | Medium | Solution | ||
| Best Time to Buy and Sell Stock
#Array
#Dynamic Programming | Easy | Solution | ||
| Palindromic Substrings
#String
#Dynamic Programming | Medium | Solution | ||
| Longest Palindromic Substring
#String
#Dynamic Programming | Medium | Solution | ||
| Best Time to Buy and Sell Stock with Cooldown
#Array
#Dynamic Programming | Medium | Solution | ||
| Maximum Product Subarray
#Array
#Dynamic Programming | Medium | Solution | ||
| Triangle
#Array
#Dynamic Programming | Medium | Solution | ||
| Minimum Path Sum
#Array
#Dynamic Programming
#Matrix | Medium | Solution | ||
| Perfect Squares
#Math
#Dynamic Programming
#BFS | Medium | Solution | ||
| Regular Expression Matching
#String
#Dynamic Programming
#Recursion | Hard | Solution | ||
| Interleaving String
#String
#Dynamic Programming
#BFS | Medium | Solution | ||
| Best Time to Buy and Sell Stock with Transaction Fee
#Array
#Dynamic Programming
#Greedy | Medium | Solution |
Greedy 6 problems
| Problem | Difficulty | Solution | Link | |
|---|---|---|---|---|
| Jump Game
#Array
#Greedy
#DP | Medium | Solution | ||
| Jump Game II
#Array
#Greedy
#DP | Medium | Solution | ||
| Gas Station
#Array
#Greedy | Medium | Solution | ||
| Meeting Rooms II
#Array
#Greedy
#Sorting | Medium | Solution | ||
| Minimum Number of Arrows to Burst Balloons
#Array
#Greedy
#Sorting | Medium | Solution | ||
| Candy
#Array
#Greedy | Hard | Solution |
Backtracking 14 problems
| Problem | Difficulty | Solution | Link | |
|---|---|---|---|---|
| Permutations
#Array
#Backtracking | Medium | Solution | ||
| Subsets
#Array
#Backtracking
#Bit Manipulation | Medium | Solution | ||
| Combination Sum
#Array
#Backtracking | Medium | Solution | ||
| Word Search
#Array
#Matrix
#Backtracking | Medium | Solution | ||
| Letter Combinations of a Phone Number
#Hash Table
#String
#Backtracking | Medium | Solution | ||
| Generate Parentheses
#String
#Dynamic Programming
#Backtracking | Medium | Solution | ||
| N-Queens
#Array
#Backtracking | Hard | Solution | ||
| Palindrome Partitioning
#String
#Dynamic Programming
#Backtracking | Medium | Solution | ||
| Combination Sum II
#Array
#Backtracking | Medium | Solution | ||
| Subsets II
#Array
#Backtracking
#Bit Manipulation | Medium | Solution | ||
| Next Permutation
#Array | Medium | Solution | ||
| Find all permutations of a string
#String | Medium | Solution | ||
| Find all permutations of a given string without duplicates
#String | Medium | Solution | ||
| Longest Valid Parentheses
#String | Easy | Solution |
Trie 3 problems
| Problem | Difficulty | Solution | Link | |
|---|---|---|---|---|
| Implement Trie (Prefix Tree)
#Design
#Trie | Medium | Solution | ||
| Word Search II
#Array
#String
#Backtracking | Hard | Solution | ||
| Replace Words
#Array
#Hash Table
#String | Medium | Solution |
Union Find 6 problems
| Problem | Difficulty | Solution | Link | |
|---|---|---|---|---|
| Redundant Connection
#Graph
#Union Find
#DFS | Medium | Solution | ||
| Accounts Merge
#Graph
#Union Find
#DFS | Medium | Solution | ||
| Number of Provinces
#DFS
#BFS
#Union-Find | Medium | Solution | ||
| Satisfiability of Equality Equations
#Array
#String
#Union-Find | Medium | Solution | ||
| Swim in Rising Water
#Array
#Binary Search
#DFS | Hard | Solution | ||
| Most Stones Removed with Same Row or Column
#Hash Table
#DFS
#Union-Find | Medium | Solution |
Monotonic Stack 5 problems
| Problem | Difficulty | Solution | Link | |
|---|---|---|---|---|
| Largest Rectangle in Histogram
#Array
#Stack
#Monotonic Stack | Hard | Solution | ||
| Sum of Subarray Minimums
#Array
#Dynamic Programming
#Stack | Medium | Solution | ||
| Online Stock Span
#Stack
#Design
#Monotonic Stack | Medium | Solution | ||
| 132 Pattern
#Array
#Binary Search
#Stack | Medium | Solution | ||
| Stock Span Problem
#Stack | Medium | Solution |
Topological Sort 4 problems
| Problem | Difficulty | Solution | Link | |
|---|---|---|---|---|
| Course Schedule
#Graph
#DFS
#BFS | Medium | Solution | ||
| Course Schedule II
#Graph
#DFS
#BFS | Medium | Solution | ||
| Parallel Courses
#Graph
#Topological Sort
#BFS | Medium | Solution | ||
| Alien Dictionary
#Array
#String
#Graph | Hard | Solution |
Bit Manipulation 5 problems
| Problem | Difficulty | Solution | Link | |
|---|---|---|---|---|
| Single Number
#Array
#Bit Manipulation | Easy | Solution | ||
| Missing Number
#Array
#Math
#Bit Manipulation | Easy | Solution | ||
| Reverse Bits
#Divide and Conquer
#Bit Manipulation | Easy | Solution | ||
| Sum of Two Integers
#Math
#Bit Manipulation | Medium | Solution | ||
| Single Number II
#Array
#Bit Manipulation | Medium | Solution |
Intervals 3 problems
| Problem | Difficulty | Solution | Link | |
|---|---|---|---|---|
| Merge Intervals
#Array
#Sorting | Medium | Solution | ||
| Minimum Interval to Include Each Query
#Array
#Binary Search
#Line Sweep | Hard | Solution | ||
| Meeting Rooms
#Array
#Sorting | Easy | Solution |
Matrix 7 problems
| Problem | Difficulty | Solution | Link | |
|---|---|---|---|---|
| Rotate Image
#Array
#Matrix
#Math | Medium | Solution | ||
| Spiral Matrix
#Array
#Matrix
#Simulation | Medium | Solution | ||
| Set Matrix Zeroes
#Array
#Matrix | Medium | Solution | ||
| Maximal Square
#Array
#Dynamic Programming
#Matrix | Medium | Solution | ||
| Game of Life
#Array
#Matrix
#Simulation | Medium | Solution | ||
| Search a 2D Matrix II
#Array
#Binary Search
#Divide and Conquer | Medium | Solution | ||
| Count Negative Numbers in a Sorted Matrix
#Array
#Binary Search
#Matrix | Easy | Solution |