Tag:Shift left

  • Realization of distributed generation of unique PHP flake ID

    Time:2020-12-4

    Twitter’s snowflake is widely used in distributed generation of unique UUID, and there are also many variants of the algorithm based on snowflake on the Internet. Many of the UUIDs generated by using snowflake are used in distributed scenarios. I have seen several articles on the Internet that are implemented in PHP without considering thread […]

  • Division without division

    Time:2020-11-27

    preface At the beginning of July, we challenged leetcode‘s question 29 (medium difficulty, which seems nothing to boast about). The problem requires that the function of integer division be realized without division, multiplication and modular operation. Since the divisor and divisor are integers, subtraction can be used to achieve division (what a naive idea). A […]

  • On binary (3) – bit operation and its application

    Time:2020-10-7

    0. Summary In the first two articles, we have learned the basic principle of binary (talk about binary (1)) and the four binary operations (talk about binary (2)). In this article, we will take a look at binary bit operation. Let’s first look at the bit operations: The table above lists all the bit operators […]

  • PHP implementation of snowflake to generate distributed unique ID

    Time:2020-9-13

    Twitter’s snowflake is widely used in distributed generation of unique UUID, and there are also many variants of the algorithm based on snowflake on the Internet. Many of the UUIDs generated by using snowflake are used in distributed scenarios. I have seen several articles on the Internet that are implemented in PHP without considering thread […]

  • Introduction and practice of SQL operator in PostgreSQL

    Time:2020-9-3

    Operator is the operation characteristic of database. It can simplify SQL code and save development time and improve development efficiency for text characters and some label characters. Comparison operator In PostgreSQL, the comparison operator can be used for all data types, and the operation result of the comparison operator returns a Boolean value. That is, […]

  • Displacement operation

    Time:2020-6-28

    Original code, inverse code, complement code Signed displacement operation (< and > >Signed displacement operations are divided into < (shift left) and > > (shift right). These two kinds of displacements are for complement operation. Symbol bits are involved in displacement operation. Except for the negative number to fill 1 in the high position, the […]

  • Introduction and practice of SQL operators in PostgreSQL

    Time:2020-5-26

    Operators are the operational characteristics of database. For the processing of text characters and some label characters, using operators can simplify SQL code, save development time and improve development efficiency. Comparison operator In PostgreSQL, all data types can use the comparison operator, and the comparison operator returns a Boolean value. True or false. The comparison […]