Webtagr - Technology News Summarizer

Understanding Big O Notation: A Practical Guide

2025-08-25

This article provides a clear and concise explanation of Big O notation, a method for describing algorithm performance. Using JavaScript's `sum` function as an example, it compares the differences between O(1) constant time, O(log n) logarithmic time, O(n) linear time, and O(n^2) quadratic time complexities. Visualizations and code examples illustrate the time complexities of various algorithms, including bubble sort and binary search. The article also explores techniques for improving code performance, such as avoiding `indexOf` within loops and leveraging caching to reduce redundant computations. Finally, it emphasizes the importance of empirical testing, cautioning against blindly trusting theoretical results.

Reservoir Sampling: A Solution for Random Sampling with Unknown Data Size

2025-05-08

This article provides a clear and concise explanation of reservoir sampling, an algorithm that elegantly solves the problem of fair random sampling when the total size of the data is unknown. Using the analogy of picking playing cards, the article progressively explains the algorithm's mechanics and illustrates its practical application with a log collection service example. Reservoir sampling ensures fairness while efficiently managing memory usage, preventing system crashes due to excessive data. The article also briefly touches upon algorithm extensions and applications, making it a highly recommended read for anyone interested in learning about this powerful technique.

Turing Machines: The Foundation of Computation

2024-12-21

This article provides a clear and accessible explanation of Turing machines—a theoretical model of computation. Starting with the operational principles of a Turing machine, it details its components (tape, head, program, and state) and illustrates programming techniques and capabilities through several examples, including printing characters, loops, and basic arithmetic. The article also explores computability and the halting problem, explains the concept of Turing completeness, and clarifies the connection between Turing machines and modern computers. Finally, the author provides an online editor for readers to write and run their own Turing machine programs, enhancing their understanding.