Growth Notes : 25th July, 2025 - 3rd August, 2025

Data Structures and Algorithms

Revised, practiced and solved problems on linked lists, binary search, recursion and dynamic programming : 983, 82, 322, 33, 19, 74, 61, 72, 153, 206, 92.

Key learnings :

• Time complexity analysis of Recursive/Iterative approaches for DP problems.
• In recursive DP approach, avoid passing the required result as parameter to the function, instead use it as the return type.
• Take care of NULL pointer checks, and edge cases in linked list related problems.

Aptitude and Reasoning

The approach I follow for solving a topic is : Read the formulae, attempt the questions in time constraint, revisit the unsolved/incorrect problems.

I've solved more than 15 problems for each of the 13 topics this week : Problems on Train, Clocks,Spotting errors, Letters and Symbol Series, Time and Distance, Height and distance, Simple Interest, Time and Work , Analogy, Profit and Loss, Partnership, Average, Problems on Ages, Number Series.

SQL

Studied SQL SELECT queries from the book Database Systems:

• WHERE clause with comparison operators
• Sorting - ORDER BY clause
• Aggregate functions
• GROUP BY
• SUB QUERIES

With the release of Study Mode in ChatGPT, I took the opportunity to understand LEFT and RIGHT joins. The LLM asks questions, provides hints and explains topic in a way we discuss with friends.

Solved Replace Employee ID With The Unique Identifier and Product Sales Analysis I.

Codeforces

I managed to solve only two problems this week - A2121 and B2121.

Reading

1. The Wrong Abstraction: The advice given is that, when you find yourself adding parameters and conditions to an already existing abstraction for making it work with your new feature/improvement, it's in best interest to reintroduce duplication and write abstraction anew.
2. 6 Simple Strategies to Cracking Any Tech Interview : Straight-forward advice and tips for performing well in interviews.
3. Don't Wait, Learn - The Best Resource is Mythical : It doesn't matter where you learn from - books, papers, courses, youtube, etc. Keep learning consistently. Don't wait for perfect learning resource.
4. A Comprehensive Survey on Vector Database: Storage and Retrieval Technique, Challenge: I'm still reading the paper, it's a comprehensive review of algorithms used in vector databases particularly for solving Approximate Nearest Neighbour Search (ANNS) problem.
5. Of Mice and Men: Short novella by John Steinback. It's a nice read, with a sad ending.

Exploration

• What are the underlying data structures used in text editors?
• How does tokenization work? What is Byte-Pair Encoding?
• Youtube recommended me this song, and I've been hooked. Best.

Questions

1. What happens when we delete a file/folder from the computer? Where does the bits go? I mean the disk can understand only 0s and 1s then how does it differentiate between data being present or not? Is delete operation similar to replacing the data with a predetermined sequence of bits which the disk understands as free storage to write into again?
2. What are the responsibilities of a person who is in a position of power over others (Teachers over students, Project leads over employees, etc)? Should one be partial for those who are good? Should a professor consider a late submission from a student who submitted hard-copy on time but forgot to turn-in on classroom?
3. Should an employee work after he leaves the company even after he/she serves the notice period because the company has not given certificate of completion and salary yet? How to handle such situations, keep your calm and move ahead?
4. How the SQL JOINS are executed under the hood? I get confused to understand which type of JOIN needs to be applied.

That's it! Until next week!