Software Engineer's Blog

Blog posts — page 39

217. Contains Duplicate

Coding Interview

217. Contains Duplicate

Jason Yang · 27 Nov, 2025

Contains Duplicate (LeetCode 217): compare the brute-force, sorting, and hash-set approaches — and why 'just use a hash set' isn't always the right reflex.

Understanding Java Exception Hierarchy

Programming Language

Understanding Java Exception Hierarchy

Jason Yang · 27 Nov, 2025

Understand Java's Throwable hierarchy — Error vs Exception, checked vs unchecked, and RuntimeException — to write safer error handling in production apps.

121. Best Time to Buy and Sell Stock

Coding Interview

121. Best Time to Buy and Sell Stock

Jason Yang · 26 Nov, 2025

Best Time to Buy and Sell Stock (LeetCode 121): the single-pass O(n) solution that tracks the lowest price so far, with an interactive step-by-step visual.

Vim Setup with vim-plug on Ubuntu

Linux

Vim Setup with vim-plug on Ubuntu

Jason Yang · 26 Nov, 2025

Set up Vim with vim-plug on Ubuntu step by step: create the required directories, configure your .vimrc for a better coding setup, and install plugins.