Coding Problems
Convert Postfix expression to Infix
All anagrams of a given string
Rain water trapping problem
Print right view of binary tree
Clone a linked list with Next and Random pointer
Diameter of a binary tree
Longest Inclusive Range Pair
Zigzag Traversal of a binary tree
Given N lockers and the location of a person, determine the nearest locker where the person can drop a package (location is represented by coordinates (x, y)).
Modified Tree, Trie (video explanation)
Weather data problem - Find min and max temperatures among 5 stations over time
Form string B from string A by reordering/ignoring characters + min steps to reach
Lowest Common Ancestor of a Binary Tree III (LeetCode)
Track user visits API + return first user who visited only once + return first N unique users
Calculate K-most popular items in a stream (event_id, item_id, timestamp)
Employee compensation by manager ID using a file with salary data
Word search problem
LFU cache implementation
Concatenated words problem (LeetCode)
Unix file search API design problem (OOD)
Buy and Sell Stocks problem
Meeting Room problems:
Find min number of rooms required
Maximum number of rooms booked at a time
Data Stream problem - find repeated frames in a video within k range
Course Schedule II (LeetCode)
Word Ladder and Word Ladder II problems
Gas Station problem
Path Sum II problem
Reverse Linked List II
Prefix sum problem
Row with maximum ones (LeetCode)
Maximum sum without adjacent elements (House Robber)
Largest binary tree in a BST problem
Sliding Window Maximum problem (LeetCode)
Substring problem related to finding pairs
Deleting a node from a BST
Seats allocation using Greedy approach
Compare Version Numbers (LeetCode)
Merge n sorted lists
Number of ways to group n people in k groups in increasing order
Min Stack implementation
Max path sum in a graph
LRU cache implementation
Asteroid Collision problem (LeetCode)
Alien Dictionary problem
Basic LPS (Longest Palindromic Subsequence)
You are given two positive integers startPos and endPos.
Initially, you are standing at position startPos on an infinite number line.
With one step, you can move either one position to the left, or one position to the right.
Given a positive integer k, return the number of different ways to reach the position endPos starting from startPos,
such that you perform exactly k steps.
Since the answer may be very large, return it modulo 10^9 + 7.
Two ways are considered different if the order of the steps made is not exactly the same.
Note that the number line includes negative integers
You are given a network of n devices, labeled from 1 to n.
You are also given times, a list of travel times as directed edges times[i] = (ui, vi, wi),
where ui is the source device, vi is the target device, and wi is the time it takes for a signal to travel from source to target.
We will send a signal from a device k. Return the minimum time it takes for all the n devices to receive the signal.
If it is impossible for all the n devices to receive the signal, return -1.

Given an array representing delivery centers location, and a distance d. Calculate total suitable location in the number line. A location is suitable if it is possible to bring all products to that point by traveling a distance of no more than d.
Example: centers = [-2,1,0], d = 8
Answer: 3 (because the only suitable locations are {-1, 0, 1} ).
Explanation: Location 1 is a suitable one because total distance traveled to bring all products to location 1 is 2*|1-(-2)|+2*|1-1|+2*|1-0| = 8 which is <=d.

LP

1. Ownership, Learn and Be Curious, Deliver Results
   LP1: Tell me about a time when you had to learn a completely new skillset to accomplish current deliverables.
   LP2: Tell me about a time when you faced a roadblock. How did you approach it? Was it solved or not? What did you learn?
   Additional: Tell me about a time when you took complete ownership of a project and ensured its success.
   Additional: Describe a situation where you saw an opportunity to improve a process and took action.
2. Customer Obsession, Ownership
   LP1: Tell me about a time when you saw a peer struggling and how you helped them.
   LP2: Tell me about a time when you went above and beyond to serve a customer. Why did you do it? How did it impact them?
   Additional: Describe a situation where you prioritized customer feedback over other priorities and the result.
3. Dive Deep, Invent and Simplify
   LP1: Tell me about a situation where you had to do an in-depth analysis to find a solution. How did you approach it? What was the impact?
   LP2: Tell me about a time when you did something innovative. What was it, and what was the outcome?
   Additional: Describe a time when you found a simple solution to a complex problem.
   Additional: Tell me about a time when you simplified an existing process without compromising on quality.
4. Have Backbone, Earn Trust
   LP1: Tell me about a time when you took an unpopular stance, and your team members or manager disagreed. How did you navigate the situation?
   LP2: Tell me about a time when you had to communicate a difficult decision or change in timeline/direction. What was it, and how did you handle it? Could anything have been better?
   Additional: Share an experience when you had to defend your ideas despite significant opposition.
   Additional: Tell me about a time when you had to make a decision that was best for the team but initially met with resistance.
5. Customer Impact, Deep Dive
   Q1: Tell me about a time when you created an impact in a customer's life. Follow-up: How did you measure the impact?
   Q2: Tell me about a time when you used customer feedback to improve a product. Follow-up: What specific feedback and changes were made?
   Additional: Describe a situation where a deep dive into data led to an unexpected discovery.
6. Bias for Action, Deliver Results
   Q1: Tell me about a time when you worked under strict deadlines. How did you manage to complete the task? What steps did you take? What approach could you have done differently?
   Q2: Tell me about a time when you could not meet a deadline. How did you communicate this to leadership? What steps did you take, and what led to the delay?
   Additional: Share an experience when you had to act quickly without having all the necessary data.
   Additional: Tell me about a situation where you took a calculated risk. What was the outcome?
7. Insist on the Highest Standards
   LP1: Tell me about a time when you saw a project that was not meeting your standards. How did you address it?
   Additional: Describe a situation where you helped raise the quality bar on a project or task.
8. Are Right, A Lot
   Q1: Tell me about a time when you made a tough decision with limited data.
   Additional: Share a time when you made a decision that turned out to be incorrect. What did you learn from it?
9. Think Big
   Q1: Describe a time when you proposed an ambitious idea. What was it, and how did you get buy-in?
   Additional: Tell me about a project where you had to look at the bigger picture and influence others to align with your vision.
10. Frugality
    Q1: Give an example of a time when you had to do more with less.
    Additional: Describe a situation where you found a cost-effective solution without compromising on quality.
11. Deliver Results
    LP1: Tell me about a challenging project and how you ensured it was delivered on time.
    Additional: Describe a situation where you prioritized competing tasks and still delivered successful results.
    This organized set covers various Amazon Leadership Principles with questions tailored for a tech interview, adding depth to your preparation for SDE2 interviews.

LLD (Low-Level Design):

Design an extensible solution to implement a search filter in OOD for a directory, matching files by size or name.
Design a library to read a directory and perform operations such as filtering by file type and size constraints.
Design a job scheduler.
Design an inventory management system with queuing for incoming requests.
Design a data structure similar to a HashMap.
Create a class diagram for a standalone chess game and explain design decisions with pseudo code for piece movements.
Create the low-level design of a download manager capable of handling multiple downloads.

HLD (High-Level Design):
Discuss what happens when a user clicks on amazon.com.
Explain the architecture of BookMyShow.
Rate limiter system design
Explain the architecture of a project from your resume with class diagrams.
Design a WhatsApp-like service, detailing load balancing, microservice communication, notification services, message queuing, database sharding, and maintaining message sequence with unreliable client timestamps.
Design MakeMyTrip with detailed component design, database diagrams, and APIs used, discussing pros and cons of each component.
Design a system to update a Mars Rover.
Design a solution for Google Photos.
Design a system that processes messages from one queue, classifies them, and outputs to another, handling 200,000 messages per second.
Implement an unbounded set with expiration.
Design a system for Amazon warehouses to prioritize truck deliveries.
Design YouTube architecture.
Design an e-commerce platform.
Create a system that identifies word matches from a dictionary, such as prefix and suffix matches.
Design an app store allowing authors to publish apps and users to download, ensuring scalability and global availability.
Design a search engine.
Design a file system to create files, add content, list files from directories, create directories, and search for files.