This category stores my personal info in English.
Problem: Since this afternoon, xfinity drops my lenovo yoga 2 laptop Wifi connection frequently. My laptop keeps reconnecting to the xfinity every 10 seconds. Process: First I suspected there are some problems with my laptop internet card driver, since my other device, smartphone and ipad, all works fine. I followed […]
Writing a Library Exception Always throw exception as early as possible. // DO class Animal{ static final String name; static { name = LoadNameFromDisk() if (name == null) { throw IllegalStateException(“Can not read name from disk”); // Throw exception here } } public Animal(){} } // DON’T class Animal{ static […]
Use of Channel package main import “golang.org/x/tour/tree” import “fmt” // Walk walks the tree t sending all values // from the tree to the channel ch. func Walk(t *tree.Tree, ch chan int){ _Walk(t, ch) close(ch) } func _Walk(t *tree.Tree, ch chan int){ if t.Left != nil{ _Walk(t.Left, ch) } ch […]
Just select YaleSecure, when the “authentication required” window opens do the following: Authentication: PEAP Anonymous identity: leave it empty CA certificate: (None) PEAP version: Automatic Inner authentication: MSCHAPv2 and of course fill in your username and password, click Connect, it will then open a new window saying that you didnt […]
This is the note for the course Neural Networks in Coursera. Course Link: https://class.coursera.org/neuralnets-2012-001/lecture Why do we need machine learning In a typical program, we define a lot of rules, which are represented by ‘loop’, ‘if condition’ and ‘assignment’. If the program is correct, given some inputs, we can always get […]
In technical interviews, many candidates are asked to implement recursion algorithms using iteration. Generally, an algorithm implemented in iteration will run faster than that in recursion, since it avoids the overhead of function call. With the help of a stack and careful algorithm design, we can convert all recursion algorithms […]
Coursera Note Sentence in red is my own perspective, inspired by the instructor. 1.1 Programming Paradigms Imperative Programs and Computers There is strong correspondence between Mutable variables ~ Memory cells Variable dereference ~ load instructions Variable assignments ~ store instructions Control structures ~ jumps Problem: how can we avoid conceptualizing […]
Motivation The difference between threads and processes used to confused me. Why do we need threads since we already have processes to support concurrency? What’s the mechanism of the context switch between threads?(rather than processes) How is locks implemented? This article may be your answer. Acknowledgement: Some of the sentences […]
Generating maze is amazing! This algorithm is also widely used in lots of computer games. Given a 2D array, generate a maze in it. There are several requirements of this maze: There are no circles in the maze, which means all roads in the maze lead to an dead end or to […]
type ls -al in the terminal Privilege: There are 10 bits in privilege part. bit 1: [d] – directory [-] – file [l] – link file [b] – interface devices [c] – serial port devices, such as mouse, keyboard bit 2-4: privilege of the file owner. read, write and execute […]
