Amazon most frequently asked DSA interview squestions

Sonika | @Walmart | Frontend Developer | 11 Years

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Apr 12, 2025

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🔁 1. Arrays & Sliding Window

• Two Sum (LeetCode #1)
• Maximum Subarray (Kadane’s Algorithm)
• Subarray Sum Equals K
• Find the Duplicate Number
• Longest Substring Without Repeating Characters

🧵 2. Strings

• Group Anagrams
• Valid Anagram
• Longest Palindromic Substring
• Minimum Window Substring
• String Compression

🧮 3. Hashing

• Top K Frequent Elements
• Intersection of Two Arrays
• Isomorphic Strings
• Longest Consecutive Sequence

🧭 4. Trees

• Lowest Common Ancestor (Binary Tree / BST)
• Binary Tree Level Order Traversal
• Invert Binary Tree
• Serialize and Deserialize Binary Tree
• Validate Binary Search Tree

🔗 5. Linked Lists

• Reverse a Linked List
• Merge Two Sorted Lists
• Detect Cycle in Linked List (Floyd’s Cycle Detection)
• Remove Nth Node From End of List
• Reorder List