add:自动拉取题解&自动生成json

Author: zhenbushidashen

README.md

@@ -15,8 +15,10 @@
 |---App.js 主逻辑都在这里
 ```
 
-## 构建
 
+
+## 构建
+- npm run auto 自动生成问题解答json
 - npm run build
 - 然后将 build 文件夹的内容添加到扩展中即可，具体方式见上面的`功能介绍`。
 

package-lock.json

@@ -15,7 +15,9 @@
     "start": "react-scripts start",
     "build": "react-scripts build",
     "test": "react-scripts test",
-    "eject": "react-scripts eject"
+    "eject": "react-scripts eject",
+    "auto": "node scripts/curl-leetcode.js && node scripts/generate-leetcode.js"
+    
   },
   "eslintConfig": {
     "extends": "react-app"
@@ -31,5 +33,10 @@
       "last 1 firefox version",
       "last 1 safari version"
     ]
+  },
+  "devDependencies": {
+    "cheerio": "^1.0.0-rc.3",
+    "iconv-lite": "^0.5.1",
+    "log4js": "^6.3.0"
   }
 }

package.json

@@ -0,0 +1,66 @@
+
+
+const request = require('request')
+const Iconv = require('iconv-lite')
+const cheerio = require('cheerio')
+const Logger = require('./Logger')
+
+
+
+class LeetCodeProvider {
+    
+
+    static getInstance() {
+        return this.oInstance || (this.oInstance = new LeetCodeProvider)
+    }
+
+    getProblemsTitle() {
+        return new Promise((ok,unExpect) => {
+
+            Logger.success('正在获取问题列表...')
+
+            request({
+                method:'GET',
+                url:'https://github.com/azl397985856/leetcode/tree/master/problems',
+                encoding:null},
+                (error,response,body) => {
+                 if(error) {
+                    unExpect(Logger.error('获取问题列表失败',error) && error)
+                 } else {
+                    let aProblemTitles =[]
+                    let sHtml = Iconv.decode(body, 'utf-8').toString()
+                    cheerio.load(sHtml)('.js-navigation-item .content .js-navigation-open ').each((idx,ele)=> aProblemTitles.push(ele.attribs['title']) )
+                     Logger.success('获取问题列表成功')
+                     ok(aProblemTitles)
+                 }
+            })
+
+        })
+    } 
+
+    getProblemDetail(problemNameWithExt) {
+        return new Promise((ok, unExpect) => {
+
+        Logger.success('正在抓取问题:', problemNameWithExt)
+
+        request({
+          method:'GET',
+          url:`https://raw.githubusercontent.com/azl397985856/leetcode/master/problems/${problemNameWithExt}`,
+            encoding:null
+        },
+        (error,response,body) => {
+        if (error) {
+            unExpect(Logger.error(`抓取问题 "${problemNameWithExt}" 失败`,error) && error)
+        } else {
+            let markdown = Iconv.decode(body, 'utf-8').toString()
+            Logger.success(`抓取问题 "${problemNameWithExt}" 成功！`)
+            ok(markdown)
+        }
+        
+    })
+})
+}
+
+}
+
+module.exports = LeetCodeProvider

scripts/LeetCodeProvider.js

@@ -0,0 +1,24 @@
+
+const log4js = require("log4js");
+
+const logger = log4js.getLogger()
+
+logger.level = 'debug'
+
+logger.category = 'LeetCode'
+
+class Logger {
+
+
+
+    static success(...args) {
+      logger.info(...args)
+    } 
+
+    static error(...args) {
+        logger.error(...args)
+    }
+
+}
+
+module.exports = Logger

scripts/Logger.js

@@ -0,0 +1,10 @@
+
+
+
+module.exports  = {
+    support_language: [
+        'java',
+        'python',
+        'javascript'
+    ]
+}

scripts/constants.js

@@ -0,0 +1,64 @@
+const LeetCodeProvider = require('./LeetCodeProvider')
+
+const Logger = require('./Logger')
+
+const Utils = require('./utils')
+
+/**
+ * 请求处理频率 ms
+ */
+const requestRate = 300 
+
+/**
+ * 当前请求问题索引
+ */
+let requsetNumber = 0
+
+
+const getProblemDetail = (questionsName, requsetNumber) => {
+    
+const cachedFilesName = Utils.getDirsFileName('spider/row-markdown')
+  
+if ( cachedFilesName.includes(questionsName[requsetNumber]) ) {
+
+    Logger.success(`${questionsName[requsetNumber]}命中缓存， 跳过。。。`)
+
+    requsetNumber++
+
+    setTimeout(() => {
+             
+        getProblemDetail(questionsName, requsetNumber)
+        
+    }, requestRate)
+}
+ else {
+
+    questionsName[requsetNumber] && LeetCodeProvider.getInstance().getProblemDetail(questionsName[requsetNumber]).then(markDown => {
+       
+        Logger.success(`问题: "${questionsName[requsetNumber]}" | 结果： ${JSON.stringify(markDown)}`)
+         
+        Utils.writeFileSync('spider/row-markdown/',questionsName[requsetNumber],markDown)
+
+        requsetNumber++
+    }).catch(Logger.error).then(() => {
+      
+         setTimeout(() => {
+             
+             questionsName[requsetNumber] && getProblemDetail(questionsName, requsetNumber)
+
+         }, requestRate)
+    })
+ }
+
+}
+
+
+LeetCodeProvider.getInstance().getProblemsTitle().then(questionsName => {
+
+    getProblemDetail(questionsName, requsetNumber)
+    
+})
+
+
+
+

scripts/curl-leetcode.js

@@ -0,0 +1,74 @@
+const Utils = require('./utils')
+const Logger = require('./Logger')
+const { support_language } = require('./constants')
+
+
+
+
+const genertateLeetcodeToJson = () => {
+const rowMarkdowns = Utils.getDirsFileName('spider/row-markdown')
+  
+rowMarkdowns.forEach(filename => {
+ 
+  let languageResloved = []
+  let markdown
+ 
+  try {
+
+   Logger.success(`开始读取${filename}`)
+
+   markdown = Utils.readFileSync(`spider/row-markdown/`,filename)
+
+   Logger.success(`读取${filename}完毕`)
+
+  }
+  catch (error) {
+
+    Logger.error(`读取${filename}失败`,error)
+  }
+   
+  
+  /**
+   *  此替换是为了解决正则匹配java时出现的问题
+   */
+
+   markdown = markdown.replace(/```javascript/g, '```js')
+    
+   support_language.forEach(lang => {
+       
+    markdown.replace(Utils.genRegByLang(lang), (noUseMatch, $1) => {
+
+        languageResloved.push({
+            lang,
+            code: $1
+        })
+
+    })
+     
+
+    let oCustomStruct = {
+      question: filename.slice(0,-3),
+      companys: ['TODO'],
+      tags: ['TODO'],
+      reslove: languageResloved
+    }
+
+    
+
+    Logger.success(`开始生成 "${filename}"`)
+    
+    Utils.writeFileSync('spider/yield-db-json',`${filename.slice(0,-3)}.json`, JSON.stringify(oCustomStruct, null, 2))
+    
+    Logger.success(`生成 "${filename}" 完毕`)
+
+   })
+   
+
+
+
+ })
+
+
+}
+
+genertateLeetcodeToJson()

scripts/generate-leetcode.js

@@ -0,0 +1,46 @@
+const fs = require('fs')
+const { resolve : pathResolve } = require('path')
+
+ const { support_language } = require('./constants')
+
+
+class Utils  {
+  
+
+    /**
+     * 获取不同语言的正则表达式
+     *
+     * @static
+     * @param {*} lang
+     * @returns
+     * @memberof Utils
+     */
+    static genRegByLang(lang) {
+        return new RegExp( `(?:\`\`\`${lang})((.|[\r\n])*?)(?:\`\`\`)`,'g')
+    }
+
+
+    static readFileSync(relativePath,filename) {
+       return fs.readFileSync(pathResolve(__dirname, '../',relativePath,filename),{encoding:'utf8'}) 
+    }
+
+    static getDirsFileName(dir) {
+       return fs.readdirSync(pathResolve(__dirname, '../', dir), {encoding:'utf8'})
+    }
+
+
+
+    static writeFileSync(dir,name,content) {
+       fs.writeFileSync(pathResolve(__dirname, '../', dir ,name),content)
+    }
+
+
+
+}
+
+
+
+
+
+
+module.exports  = Utils

scripts/utils.js

@@ -0,0 +1,50 @@
+## Problem
+https://leetcode-cn.com/problems/two-sum
+
+## Problem Description
+```
+Given an array of integers, return indices of the two numbers such that they add up to a specific target.
+
+You may assume that each input would have exactly one solution, and you may not use the same element twice.
+
+Example:
+
+Given nums = [2, 7, 11, 15], target = 9,
+
+Because nums[0] + nums[1] = 2 + 7 = 9,
+return [0, 1].
+```
+
+## Solution
+The easiest solution to come up with is Brute Force. We could write two for-loops to traverse every element, and find the target numbers that meet the requirement. However, the time complexity of this solution is O(N^2), while the space complexity is O(1). Apparently, we need to find a way to optimize this solution since the time complexity is too high. What we could do is to record the numbers we have traversed and the relevant index with a Map. Whenever we meet a new number during traversal, we go back to the Map and check whether the `diff` between this number and the target number appeared before. If it did, the problem has been solved and there's no need to continue.
+
+## Key Points
+ - Find the difference instead of the sum
+ - Connect every number with its index through the help of Map
+ - Less time by more space. Reduce the time complexity from O(N) to O(1)
+
+ ## Code
+  - Support Language: JS
+
+```js
+/**
+ * @param {number[]} nums
+ * @param {number} target
+ * @return {number[]}
+ */
+const twoSum = function (nums, target) {
+    const map = new Map();
+    for (let i = 0; i < nums.length; i++) {
+        const diff = target - nums[i];
+        if (map.has(diff)) {
+            return [map.get(diff), i];
+        }
+        map.set(nums[i], i);
+    }
+}
+```
+
+***Complexity Anlysis***
+
+- *Time Complexity*: O(N)
+- *Space Complexity*：O(N)