Lu, Yukuan

204. Count Primes

Given an integer n, return the number of prime numbers that are strictly less than n.

Dynamic programming(DP) problems that typically use one pointer. E.g., Integer[] memo.

Problems like "given an 2D binary grid grid which represents a map of land and water, return the number of islands, an island is XXXX".

• 200. Number of Islandsopen
• 1020. Number of Enclavesopen
• 1254. Number of Closed Islands
• 1905. Count Sub Islandsopen
• 695. Max Area of Island

Ref: labuladong 题解

Dynamic programming(DP) problems that typically use two pointers. E.g., Integer[][] memo.

• Edit Distance
• Longest Common Subsequence

牙齿健康的常识, 以及常见牙科手术的说明, 包括补牙(Tooth filling), 拔智齿(Wisdom Teeth Extraction), 根管治疗(Root canal therapy).

Types of bank cards. How to use them. And some special notes.

Ref: ->Everyday money

In this tutorial, we will guide you through the steps required to to install Linux(e.g., Ubuntu, Archlinux, Manjaro,...) on your Laptop or PC.

How to create the installation media, which is used to install Linux on your machine, with corresponding tools.

174. Dungeon Game

The demons had captured the princess and imprisoned her in the bottom-right corner of a dungeon. The dungeon consists of m x n rooms laid out in a 2D grid. Our valiant knight was initially positioned in the top-left room and must fight his way through dungeon to rescue the princess.

Ref: Daniel J. Velleman. (2019). HOW TO PROVE IT (3th ed., pp. 1-6). Cambridge University Press.