1. Elasticsearch Basic Concept

1. Concept

Wikipedia:

In software engineering, the singleton pattern is a software design pattern that restricts the instantiation of a class to one object.

Recently, I was confused with Cython and Cpython. In this blog, I will talk about Cython, CPython, Jython, and compare them with Java, C/C++ and related concepts.

1. Concept

Wikipedia:

Bit manipulation is the act of algorithmically manipulating bits or other pieces of data shorter than a word. Computer programming tasks that require bit manipulation include low-level device control, error detection and correction algorithms, data compression, encryption algorithms, and optimization. For most other tasks, modern programming languages allow the programmer to work directly with abstractions instead of bits that represent those abstractions. Source code that does bit manipulation makes use of the bitwise operations: AND, OR, XOR, NOT, and bit shifts.

Recently, I am developing Java API in Spring Boot Framework and learning this framework. I found a new feature from Spring Framework 4.3 that if a bean has only one constructor, @Autowired can be omitted. Then I planned to write a blog about Inversion of Control (IoC) and Dependency Injection (DI) in Spring. This article will only introduce basic definition of IoC and DI and how to use it, and I will write another blog to talk about the theory and implement of DI later. If you are just interested in the new feature, please jump to the last part.

1. 概念

百度百科：

快慢指针中的快慢指的是移动的步长，即每次向前移动速度的快慢。例如可以让快指针每次沿链表向前移动2，慢指针每次向前移动1次。

1. Concept

Quora：

Slow pointer and fast pointer are simply the names given to two pointer variables. The only difference is that, slow pointer travels the linked list one node at a time where as a fast pointer travels the linked list two nodes at a time.