Introduction to Web Worker API

Web Worker API is a JavaScript web API for running multiple tasks simultaneously without affecting the performance of the apps.

Introduction to Web Beacon API

The Beacon API is a JavaScript web API for sending data from the browser to the web server without expecting to get a response. It is used to send analytics, diagnostics, and logging data which doesn't need a response.

Unique Path III in JavaScript

On a 2-dimensional grid, there are 4 types of squares. Return the number of 4-directional walks from the starting square to the ending square, that walk over every non-obstacle square exactly once.

Largest Rectangle in Histogram in JavaScript

Given n non-negative integers representing the histogram's bar height where the width of each bar is 1, find the area of largest rectangle in the histogram.

How to calculate Euclidean Distance? How to measure the distance between two points?

Calculate the Euclidean Distance for one dimensional, two dimensional, three dimensional in JavaScript. In mathematics, the Euclidean distance or Euclidean metric is the "ordinary" straight-line distance between two points in Euclidean space.

Verifying an Alien Dictionary in JavaScript

In an alien language, surprisingly they also use english lowercase letters, but possibly in a different order. The order of the alphabet is some permutation of lowercase letters.

Longest Palindromic Substring in JavaScript

Given a string, find the longest palindromic substring. We going to iterate each character in the string; and within that character, we expand and look for the longest palindrome. As we keep iterating, we only keep the longest palindrome.

Labor Day Sale Promotion for Master Cutlery, Retail, and Top Chef Cutlery

The Labor Day is coming soon, on September 2, 2019. Master Cutlery is doing a sales promotion at its own wholesale website, Retail, and Top Chef Cutlery. Therefore, I designed a graphic in Photoshop.

Clock Angle in JavaScript

Given two integers, an hour and a minute, write a function to calculate the angle between the two hands on a clock representing that time.

Happy Birthday to the Marine Corps Reserves! Celebrate with 25% off all officially licensed u.s. marines knives

Today August 29, 2019, is the Marine Corps Reserves Birthday. I designed an graphic for Master Cutlery and Retail sale promotion. It offer 5% and 25% off all officially licensed U.S. marines knives respectively. It will be sent to all customers via email.

National Knife Day Promotion For Master Cutlery & Top Chef

Our favorite holiday of the year is this Saturday: National Knife Day! We are so excited we thought we would kick off the festivities early and make it National Knife WEEK! Celebrate with us and save an EXTRA 25% OFF ALL MTECH KNIVES ALL WEEK LONG!!

25% off all grill sets at

Summer is a time for grilling and chilling! Finish summer strong with a great new set of grilling tools found in one of our 4 awesome sets! Simply enter the code GRILL-19 when checking out and the savings will be applied to your cart. This deal ends at midnight on Saturday so don't wait! is a single page application (SPA), ecommerce website. Customers are able to browse and search catalog, add items to shopping cart, and place orders.

Knife Customization

This is the app that I wrote for Master Cutlery. You can build your own knife with this knife customization app. You get to choose handle material, bolster, box, and pouch. The visual appearance and the price of the knife will be changed based on your configuration.

Rotting Oranges

Every minute, any fresh orange that is adjacent (4-directionally) to a rotten orange becomes rotten. Return the minimum number of minutes that must elapse until no cell has a fresh orange. If this is impossible, return -1 instead.