The hottest Coding Substack posts right now

And their main takeaways
Category
Top Technology Topics

[Solution]Problem 51:Happy Number[IBM]

Technology Made Simple • 19 implied HN points • 11 Aug 22
🕹 Technology Coding
  1. A happy number is a number defined by a specific process that ends with the number 1, while an unhappy number will loop endlessly without reaching 1.
  2. When facing a problem, break down the definitions given in the problem as this can provide insights and help formulate mathematical rules for quick problem-solving.
  3. In problem-solving, looking for patterns, mathematical or algorithmic statements can give a competitive advantage and aid in solving or optimizing problems efficiently.

Problem 50:Rotting Oranges[Microsoft]

Technology Made Simple • 19 implied HN points • 03 Aug 22
🕹 Technology Coding
  1. The problem involves determining the minimum time for all fresh oranges to rot in a grid of cells with different states.
  2. Rotten oranges in the grid affect adjacent fresh oranges, causing them to rot in a specific pattern.
  3. Understanding this problem type can help in mastering similar challenges efficiently.

[Solution]Problem 49:Min Stack[Google]

Technology Made Simple • 19 implied HN points • 27 Jul 22
🕹 Technology Coding
  1. Designing a stack that supports push, pop, top, and retrieving the minimum element in constant time is a common problem in coding interviews and competitive programming.
  2. Implementing a solution for the Min Stack problem requires tracking the minimum element seen up to each layer of the stack using two stacks for efficiency.
  3. Building a base solution for the Min Stack problem by initializing two stacks, and optimizing the solution by removing redundancies can distinguish a good solution from a great one in interviews.

Problem 48:Valid Parentheses[Amazon]

Technology Made Simple • 19 implied HN points • 20 Jul 22
🚌 Education Coding
  1. The post discusses the classic coding interview problem of determining whether a string of parentheses, brackets, and braces is valid.
  2. The examples provided illustrate how to determine if a string of characters follows the rules of valid parentheses.
  3. Resources are shared for further practice, including a link to the problem on Leetcode and a survey request to help feature the publication.

Software engineering practices you should probably be following in 2024

The Tech Enabler • 3 HN points • 27 Feb 24
🕹 Technology Coding
  1. Prefer statically typed languages over dynamically typed ones as they offer better reliability and help catch errors earlier.
  2. Utilize automatic code formatting tools for consistent code style and to save time on debating formatting during code reviews.
  3. Consider using queues as data sources in event-driven systems for better scalability and leverage infrastructure-as-code tools like Terraform for repeatable and manageable infrastructure.
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[Solution]Problem 45:Robot Bounded In Circle [Amazon]

Technology Made Simple • 19 implied HN points • 07 Jul 22
🕹 Technology Coding
  1. Math and logic are essential in problem-solving as they can help analyze and solve complex scenarios.
  2. Understanding periodicity in functions can be applied to analyze repetitive patterns in problems with infinite instructions.
  3. Analyzing the impact of direction and location in a periodic function can reveal insights on the behavior of a system over time, leading to accurate solutions.

Problem 45:Robot Bounded In Circle [Amazon]

Technology Made Simple • 19 implied HN points • 06 Jul 22
🚌 Education Coding
  1. The problem describes a scenario where a robot moves on an infinite plane following specific instructions and determines if it remains within a circle.
  2. The instructions for the robot include moving one unit forward, turning left or right by 90 degrees, and endlessly repeating those instructions.
  3. By understanding the movement of the robot based on the given instructions, it is possible to determine if the robot stays within a circle on the plane.

Problem 2: Find all occurrences of Substring Solution [Microsoft] (Example of Solutions in Paid Version)

Technology Made Simple • 39 implied HN points • 23 Aug 21
🕹 Technology Coding
  1. When solving problems, start with a simple solution even if it's not optimal. It's better to have a working brute-force solution than no solution at all.
  2. Optimizing code involves identifying and eliminating redundant parts. For instance, in string matching problems, consider using techniques like hashing to improve efficiency.
  3. The Rabin-Karp algorithm is a rolling hash function used for string searching. It involves using hashes to compare substrings efficiently, reducing false positives and improving overall performance.

Problem 44: Longest Substring Without Repeating Characters (Meta / Facebook)

Technology Made Simple • 19 implied HN points • 29 Jun 22
🕹 Technology Coding
  1. Problem 44 focuses on finding the longest substring without repeating characters, a common challenge in coding interviews.
  2. The problem involves using techniques like Two Pointers, Arrays, and Hashmaps for efficient duplicate checking.
  3. Examples provided help understand the problem, emphasizing the importance of finding unique substrings.

Problem #1 Solution

Technology Made Simple • 39 implied HN points • 15 Aug 21
🕹 Technology Coding
  1. Identifying recursion problems involves going over example cases by hand, which is a helpful practice for debugging and handling edge cases.
  2. This particular problem is marked as medium difficulty but lies at the lower end of the medium spectrum, requiring a solid understanding to tackle effectively.
  3. Engaging in a 7-day free trial subscription can provide access to more detailed solutions and additional content in the post archives.

How to Spot Greedy Algorithms[Techinque Tuesdays]

Technology Made Simple • 19 implied HN points • 22 Jun 22
🕹 Technology Coding
  1. Greedy algorithms make decisions based on immediate benefit, without looking ahead to future consequences.
  2. To identify a greedy algorithm, look for problems that can be broken into sub-problems, where the optimal solution of each sub-problem contributes to the overall optimal solution.
  3. Improving at recognizing greedy algorithms requires practice and analysis of problems to refine your intuition.

Hello, world !

Women On Rails Newsletter - International Version • 39 implied HN points • 21 Jun 21
🌐 International Coding
  1. Women On Rails Newsletter shares news on the Ruby and Rails community, selected articles on web news and code tips, and something to get inspired.
  2. The newsletter is available in English, translated by Aurelie and Stefanni, opening up the content to a wider audience.
  3. You can subscribe to the newsletter and also share it with your friends to spread the knowledge and inspiration further.

Reducing selection bias / popularity bias in ranking

Recommender systems • 26 implied HN points • 20 Jan 24
🕹 Technology Coding
  1. Reducing selection bias and popularity bias in ranking is important for recommender systems.
  2. An advocated approach is to factorize user interaction signals to account for biases originating from power users and power items.
  3. The proposals for causal/debiased ranking involve factorization, mutual information, and mixture of logits to improve the ranking model.

[Solution]Problem 39: Find the Celebrity[Pintrest]

Technology Made Simple • 19 implied HN points • 27 May 22
🕹 Technology Coding
  1. The problem involves finding a celebrity at a party who everyone knows, but who doesn't know anyone in return. A brute force approach of comparing every pair of people at the party can be used, but it is slow with O(N^2) complexity.
  2. It is essential to analyze why a solution is inefficient to brainstorm and develop an optimal solution efficiently. By utilizing constraints given in the problem, like the knowledge asymmetry between the celebrity and others, the time and space complexity can be significantly reduced to O(N) and O(1) respectively.
  3. In problem-solving, understanding and applying constraints effectively can lead to substantial improvements in both time and space complexity, making solutions more efficient and optimal.

Go fix your bugs

Basta’s Notes • 40 implied HN points • 04 May 23
🕹 Technology Coding
  1. Always validate the types of values your API accepts to prevent potential security vulnerabilities.
  2. Be cautious with regular expressions to avoid performance issues like ReDoS (Regular Expression Denial of Service).
  3. Check and handle subdomains and domain name validation to prevent unexpected bugs or failures in your application.

Problem 35: 3 Sum[Netflix]

Technology Made Simple • 19 implied HN points • 28 Apr 22
🕹 Technology Coding
  1. Understanding the 3 Sum problem is crucial for coding interviews, as it's a common question with useful problem-solving tricks.
  2. The 3 Sum problem involves finding triplets in an integer array that sum up to zero, while ensuring no duplicates in the solution set.
  3. It's important to have prior experience or knowledge to tackle the 3 Sum problem effectively during interviews.

[Solution]Problem 31:Maxium Rainwater Trapping[Microsoft]

Technology Made Simple • 19 implied HN points • 01 Apr 22
🕹 Technology Coding
  1. Understanding the problem thoroughly is essential in tackling difficult coding challenges. Break down the problem into smaller components and focus on each step.
  2. Identifying patterns and creating systems can help simplify complex problems. Mathematics can be a powerful tool in problem-solving and coding interviews.
  3. Utilizing techniques like the two-pointer approach can be incredibly helpful in optimizing solutions and acing technical interviews.

Problem 30: Find Distance to nearest Exit[Google]

Technology Made Simple • 19 implied HN points • 24 Mar 22
🕹 Technology Coding
  1. The problem involves finding the distance to the nearest exit on a 2D grid with obstacles and gates.
  2. The solution requires filling each empty room with the distance to its nearest gate, considering obstacles and walls.
  3. This question is a favorite problem asked by Google to test problem-solving skills and the ability to recognize the right approach.

[Solution]Problem 29: Arranging Coins in Staircase[Netflix]

Technology Made Simple • 19 implied HN points • 18 Mar 22
🕹 Technology Coding
  1. The problem involves arranging coins in a staircase with specific row numbers, and the solution focuses on finding the maximum number of complete rows that can be built.
  2. The solution involves analyzing the input (number of coins) and output (number of complete rows), and working through a simple approach using math to determine the complete rows.
  3. To improve the solution further, simplifications can be made to optimize the algorithm, aiming for a faster runtime complexity close to square root of n.

How would you design Twitter

Technology Made Simple • 19 implied HN points • 16 Mar 22
🕹 Technology Coding
  1. When designing a system like Twitter, it's important to approach the problem methodically and break it down into smaller sub-problems to find solutions.
  2. System design interviews don't have strict right or wrong answers, so it's okay to focus on different aspects based on your expertise.
  3. Engaging with resources and trying to solve the problem yourself first before looking at solutions can be a valuable learning approach for system design.

How to use this newsletter to improve

Technology Made Simple • 19 implied HN points • 16 Mar 22
🕹 Technology Coding
  1. Learning from coding questions involves more than just solving them; it's crucial to learn from your mistakes.
  2. Take detailed notes as you attempt problems to provide valuable feedback to track your progress.
  3. Reviewing solutions, comparing them to your own approach, and noting differences can help improve your problem-solving skills.

[Solution]Problem 28: Perfect Shuffling for a Deck of Cards[Facebook/Meta]

Technology Made Simple • 19 implied HN points • 11 Mar 22
🕹 Technology Coding
  1. Understand the problem clearly before jumping into writing code. Break down the problem into smaller parts to uncover important hints and insights.
  2. Start with a simple, naive algorithm for math/algorithm-heavy questions. This can help build intuition for more complex optimizations.
  3. Analyzing the uniformity of a solution is crucial, especially for problems with permutations like shuffling a deck of cards. Cases like odd and even numbers showcase the importance of ensuring uniform distribution.

[Solution]Problem 27: Create largest possible number using list[Amazon]

Technology Made Simple • 19 implied HN points • 02 Mar 22
🕹 Technology Coding
  1. The post discusses solving a problem from Amazon which involves arranging non-negative integers to form the largest possible number.
  2. The solution may require understanding concepts like Integer List, String Conversions, and Custom Comparitors.
  3. It highlights the importance of converting numerical results into strings when dealing with potentially very large numbers.

Clean Code: The Art of Clean Naming

Brain Bytes • 2 HN points • 06 Mar 24
🕹 Technology Coding
  1. The importance of clean and clear naming in coding cannot be overstated. Good naming makes code understandable for anyone reading it.
  2. Contextual information in variable names is crucial for code clarity and to avoid potential bugs or misuse of variables in larger codebases.
  3. Avoiding magic numbers, abbreviations, and acronyms in code improves readability and maintainability for all developers working on the codebase.

Changing my mind on whether managers should keep coding

peoplefirstengineering • 8 implied HN points • 05 Dec 24
🕹 Technology Coding
  1. It's important for managers to stay connected to coding, as it helps them empathize with their team. Being hands-on can improve understanding of the challenges engineers face.
  2. Empathy in leadership goes beyond just understanding tasks; it involves recognizing individual emotions and how they affect performance. Good managers should tailor their support based on team members' unique situations.
  3. Challenges in coding create a shared experience among team members. Managers who code can better relate to the ups and downs, building trust and a stronger team dynamic.

Problem 25: Boolean Satisfiability[Dropbox]

Technology Made Simple • 19 implied HN points • 16 Feb 22
🕹 Technology Coding
  1. A Boolean formula is satisfiable if truth values can be assigned to variables to make the entire formula true.
  2. Formulas with AND statements joining tuples containing exactly one OR are known as 2-CNF.
  3. The task is to find a way to assign truth values to a 2-CNF formula to satisfy it, or return False if it's impossible.

[Solution]Problem 22: Positive Pairs meeting conditions[Jane Street]

Technology Made Simple • 19 implied HN points • 27 Jan 22
🕹 Technology Coding
  1. The problem involves finding pairs of positive integers that satisfy specific conditions involving addition and XOR operations.
  2. Understanding binary representation and logical operators like XOR can lead to more optimal solutions for certain problems.
  3. Mathematical reasoning and logical analysis can help in optimizing solutions and reducing time complexity, especially when dealing with binary operations.

Naming Things

The 418 • 1 HN point • 06 May 24
🕹 Technology Coding
  1. Good names are crucial in programming as they become the building blocks of our shared tools, maintaining order and helping us recall resources.
  2. Well-named things should be SEO-friendly, follow conventions, be concise but meaningful, consider collisions, guessable, and even bring a smile.
  3. Injecting humor or cleverness into naming can add personality and help with team bonding, as well as make code memorable.

[Solution]Problem 18: Pack Words on Board [Google]

Technology Made Simple • 19 implied HN points • 30 Dec 21
🕹 Technology Coding
  1. The problem involves finding the maximum number of words that can be constructed from a given dictionary and a matrix of random letters.
  2. The solution to this problem involves using backtracking, a recursive algorithmic technique that incrementally builds a solution while adhering to constraints.
  3. When solving such problems, it is important to consider traversing the matrix, ensuring that letters are adjacent vertically and horizontally, and not diagonally.

Problem 18: Pack Words on Board [Google]

Technology Made Simple • 19 implied HN points • 29 Dec 21
🚌 Education Coding
  1. Given a matrix of letters and a dictionary of words, find the maximum number of words that can be constructed from the matrix based on specific rules.
  2. To pack a word on the board, it must be in the dictionary, created from available letters, and have adjacent letters (vertically and horizontally).
  3. In the example, the function should return 3 for the words 'eat, 'in', and 'rat' as valid words that can be formed without touching each other.

Problem 15: Mastermind Code Decoding [Facebook]

Technology Made Simple • 19 implied HN points • 09 Dec 21
🕹 Technology Coding
  1. Mastermind is a two-player game where one player guesses the secret code of the other player.
  2. In the game, the first player guesses a number, and the response indicates how many digits were correctly placed in the secret code.
  3. An algorithm is needed to determine if a given sequence of guesses and their scores can be produced by a particular secret code.

[Solution]Problem 14: Smallest Closed Interval [Google]

Technology Made Simple • 19 implied HN points • 03 Dec 21
🕹 Technology Coding
  1. Given a set of closed intervals, find the smallest set of numbers that covers all the intervals, allowing for multiple smallest sets to be returned.
  2. Defining intersecting intervals involves comparing the lower bound of one interval with the upper bound of another to see if they intersect.
  3. Tighten the bounds by picking the smallest intersection between two intervals, considering different kinds of intersections.

[Solution]Problem 12: Group Shifted Strings [Facebook]

Technology Made Simple • 19 implied HN points • 05 Nov 21
🕹 Technology Coding
  1. Given an array of strings, group them based on being shifted versions of each other by finding the difference in characters.
  2. Implementing a hashset can efficiently group strings by their difference strings for quick retrieval.
  3. Creating helper functions and structuring your solution neatly can showcase your organization and problem-solving skills.