Digest | 算法：幂集, 一个startup架构一个集合的幂集是它所有子集的集合。写一个函数，给定一个集合，生成它

2021年04月08日信息消化

原发布地址：Digest | 算法：幂集, 一个startup架构

每天学点算法

幂集 | Power Set

一个集合的幂集是它所有子集的集合。写一个函数，给定一个集合，生成它的幂集。

The power set of a set is the set of all its subsets. Write a function that, given a set, generates its power set.

For example, given the set {1, 2, 3}, it should return {{}, {1}, {2}, {3}, {1, 2}, {1, 3}, {2, 3}, {1, 2, 3}}.

# https://tutorialspoint.dev/algorithm/mathematical-algorithms/power-set
# python3 program for power set 
  
import math; 
  
def printPowerSet(set,set_size): 
      
    # set_size of power set of a set 
    # with set_size n is (2**n -1) 
    pow_set_size = (int) (math.pow(2, set_size)); 
    counter = 0; 
    j = 0; 
      
    # Run from counter 000..0 to 111..1 
    for counter in range(0, pow_set_size): 
        for j in range(0, set_size): 
              
            # Check if jth bit in the  
            # counter is set If set then  
            # print jth element from set  
            if((counter & (1 << j)) > 0): 
                print(set[j], end = ""); 
        print(""); 
  
# Driver program to test printPowerSet 
set = ['a', 'b', 'c']; 
printPowerSet(set, 3); 
  
# This code is contributed by mits.

每天学点Golang

使用GORM和GIN在Golang中实现简单分页功能

原文：Implement Pagination In Golang Using GORM and GIN

The packages you need to install in our project is:

go get github.com/go-sql-driver/mysql
go get github.com/gin-gonic/gin
go get github.com/jinzhu/gorm

目录结构

- /first-api
	- /Config
  - /Controllers
  - /Model
  - /Routes
  - go.mod
  - go.sum
  - main.go

核心分页部分。

config.go: DB实例
repo.go

import (
	"first/src/first-api/Config"
	models "first/src/first-api/Model"
)

func GetAllUsers(user *models.User, pagination *models.Pagination) (*[]models.User, error) {
	var users []models.User
	offset := (pagination.Page - 1) * pagination.Limit
	queryBuider := Config.DB.Limit(pagination.Limit).Offset(offset).Order(pagination.Sort)
	result := queryBuider.Model(&models.User{}).Where(user).Find(&users)
	if result.Error != nil {
		msg := result.Error
		return nil, msg
	}
	return &users, nil
}

其他值得阅读

一个startup架构概览

原文：Architecture for a startup

静态前台（Static web app）：
- S3 + CloudFront CDN + Route53
后台（Backend production system）
- EC2（auto-scaling group）+ AWS ElasticCache + MySQL (RDS) + ALB + Cognito
分析（Analytics system）
- Metabase + ALB + Cognito
监视（Monitoring）
- NewRelic free tier + self-hosted Sentry server
部署（deployment）
- Jenkins
Terraform is used for infrastructure as code
Ansible is used as configuration management.

我的妈妈在用Arch Linux

原文：My Mom Uses Arch Linux

This gist covers the whole step-by-step procedure I followed to get it up and running.

Desktop Environment: Cinnamon
Window Manager: Mutter
File Manager: Nemo
Video Player: mpv
Image Viewer: feh
Browser: Firefox

大规模Vue.js应用的4个最佳实践

原文：4 Best Practices for Large Scale Vue.js Projects

Use Vue Slots
F.I.R.S.T principle： Build & share independent components
- Bit

well organized VUEX Store

└── store
    ├── index.js          
    ├── actions.js
    ├── mutations.js
    └── modules

Unit Tests
- Jest, Karma, or Mocha

一点收获

人生是一场没有赛道的长跑。持续比强度重要。
GPT-3 learning corpus consists of the common-craw dataset. The dataset includes 45TB of textual data or most of the internet. GPT-3 is 175 Billion parameter models as compared to 10–100 Trillion parameters in a human brain. -- GPT-3 Explained to a 5-year-old