SEARCH KEYWORD -- Arrays.equal()


  Find max subarray of an array

In computer science, the maximum subarray problem is the task of finding the contiguous subarray within a one-dimensional array of numbers (containing at least one positive number) which has the largest sum. For example, for the sequence of values −2, 1, −3, 4, −1, 2, 1, −5, 4; the contiguous subarray with the largest sum is 4, −1, 2, 1, with sum 6. The problem was first posed by Ulf Grenander of Brown University in 1977,...

   Max Subarray, Divide and conquer,Kadane     2013-04-22 11:50:35

  Why localStorage only allows to store string values

localStorage allows data to be stored in browsers across sessions, the data will be there even though the session is expired. It is frequently used to store static data so that they can be loaded when needed. But as per spec, it says that the keys and the values are always strings (note that, as with objects, integer keys will be automatically converted to strings). Why cannot store the object as it is? Take a look at an example: var str = "test"; localStorage.setItem("str", str); cons...

   JAVASCRIPT,LOCALSTORAGE     2020-04-05 00:54:29

  Ways to check existence of JavaScript object

The design of JavaScript is not so sophisticated. It's very easy for us to make mistakes if we are not very careful when using JavaScript. For example, to check the existence of JavaScript object. Now we want to check whether a global object myObj exists or not, if it doesn't exist, we declare it. The pseudo code for this is : if(myObj not exist){ declare myObj; } You may think it's very easy to write the code. In fact, it is much more difficult than we may think. Juriy Zaytsev says there are m...

   JAVASCRIPT,OBJECT,EXISTENCE     2020-09-12 02:14:02

  Deep clone of JavaScript object

In JavaScript world, it's frequently seen object clone. Normally when creating a clone of an object, it's only the reference being cloned but not all contents. In some scenarioes, it's desired to clone all the content instead of just the reference such that any change made to the cloned object will not change the original object. Differences between shallow clone and deep clone can be as simple as: Shallow clone : Only the object reference is cloned but not the content Deep clone : Clone all co...

   JAAVSCRIPT,DEEP CLONE,DEEP COPY,SHALLOW CLONE,SHALLOW COPY     2016-10-31 00:27:24

  The Problem with Random Numbers

Today, let's talk about how to generate true random numbers. This is an extremely difficult problem, but it involves some very interesting content. First of all, the random numbers provided by programming languages are pseudo-random numbers.  The V8 engine’s official website has an article that particularly reminds everyone of this point. The built-in random numbers are not true random numbers but pseudo-random numbers. Math.random() returns a Number value with po...

   RANDOM NUMBER,TRUE RANDOM,PSEUDO RANDOM,HISTORY     2024-06-21 21:09:14

  Why using + to concatenate string in Java loop is not a good option

String concatenation is a common operation in Java programming. It is to concatenate multiple strings into a single string. Java provides a String class which is an immutable class which means the object cannot be mutated once instantiated. Once a String object is instantiated, its properties cannot be changed anymore, so when concatenating strings, it's actually create a new String instance to store the concatenated string values. For example, below is a simple string concatenation example. Str...

   JAVA,STRING,JAVA 8     2019-01-18 22:07:12

  Remove duplicated elements in JavaScript array

During interviews, one frequent question asked would be something like how to remove duplicated elements in a JavaScript array and how many different ways you can think of. The interviewee would also be asked to write the code down. In real applications, normally front end would not need to handle this case since normally it would be done by backend, but still it's necessary for front end developers to know different ways of doing this. This post will share some of the common ways to remove dupl...

   JAVASCRIPT,ARRAY,DUPLICATED ELEMENT     2018-09-21 22:32:10

  A simple example of git bisect command

git bisect is a very powerful command for finding out which commit is a bad commit when bug occurs.  The rationale behind this command is that it pin locates the bad commit by divide and conquer. It divides the commit history into two equal parts, then determines whether the bad commit is at the first half or at the other half. This process will continue until the bad commit is located. Here is a really good example created by bradleyboy, this is a simple git repository which demonstr...

   GITHUB,GIT,GIT BISECT     2019-07-12 10:31:51

  Password-less login

Most websites need user login in order to provide personalized content to visitors. The usual way is to request user to register an user account. Actually, this is not so appealing since if we need to remember one password for each website, it's troublesome, while for developers, it's their responsibility to protect password, once password is leaked, then it's a big headache to a website's business and reputation. So long time ago people started thinking about password-less login, this is a big ...

   Password-lesslogin,Authentication     2012-11-05 12:29:55

  Implementing DESede/ECB/NoPadding cipher algorithm in GoLang

By default, GoLang doesn't provide the ECB mode cipher for DESede though there is CBC mode provided. In cases we need to encrypt/decrypt data with ECB mode, we need to implement those by ourselves. This mode is frequently used when encrypting/decrypting PIN block which is small block data less than 16 bytes. In this post, we will introduce how to implement the DESede/ECB/NoPadding algorithm in GoLang by using the existing cipher support. Here we will not cover how DESede works in detail, instead...

   SECURITY,SAMPLE,GOLANG,DES,DESEDE,3DES     2019-07-29 06:43:50

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