feat: add 2 solutions

Author: Chersquwn

.gitignore

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+
+# Numerous always-ignore extensions
+*.bak
+*.patch
+*.diff
+*.err
+
+# temp file for git conflict merging
+*.orig
+*.log
+*.rej
+*.swo
+*.swp
+*.zip
+*.vi
+*~
+*.sass-cache
+*.tmp.html
+*.dump
+
+# OS or Editor folders
+.DS_Store
+._*
+.cache
+.project
+.settings
+.tmproj
+*.esproj
+*.sublime-project
+*.sublime-workspace
+nbproject
+thumbs.db
+*.iml
+
+# Folders to ignore
+.hg
+.svn
+.CVS
+.idea
+
+# custom
+node_modules/
+jscoverage_lib/
+bower_components/
+.rts2_cache_*
+coverage

README.md

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+// problem https://leetcode.com/problems/add-two-numbers/
+
+/**
+ * Definition for singly-linked list.
+ * function ListNode(val) {
+ *     this.val = val;
+ *     this.next = null;
+ * }
+ */
+/**
+ * @param {ListNode} l1
+ * @param {ListNode} l2
+ * @return {ListNode}
+ */
+const addTwoNumbers = function (l1, l2) {
+  let head = new ListNode(0)
+  let node = head
+  let carry = 0
+
+  while (l1 || l2) {
+    let x = l1 ? l1.val : 0
+    let y = l2 ? l2.val : 0
+    let sum = x + y + carry
+
+    carry = sum > 9 ? 1 : 0
+
+    node.next = new ListNode(sum % 10)
+    node = node.next
+
+    l1 && (l1 = l1.next)
+    l2 && (l2 = l2.next)
+  }
+
+  if (carry > 0) {
+    node.next = new ListNode(carry)
+  }
+
+  return head.next
+};

algorithms/Add Two Numbers/index.js

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+// problem https://leetcode.com/problems/two-sum/
+
+/**
+ * @param {number[]} nums
+ * @param {number} target
+ * @return {number[]}
+ */
+const twoSum = function(nums, target) {
+  const hashmap = {}
+
+  for (let i = 0; i < nums.length; i++) {
+    let other = target - nums[i]
+
+    if (hashmap[other] !== undefined) {
+      return [hashmap[other], i]
+    }
+
+    hashmap[nums[i]] = i
+  }
+}

algorithms/Two Sum/index.js

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+{
+  "name": "leetcode",
+  "version": "1.0.0",
+  "description": "LeetCode solutions with JavaScript",
+  "main": "index.js",
+  "scripts": {
+    "gen": "node scripts/generate.js",
+    "precommit": "npm run gen && git add ."
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+ssh://[email protected]/Chersquwn/leetcode.git"
+  },
+  "keywords": [
+    "leetcode"
+  ],
+  "author": "Chersquwn",
+  "license": "MIT",
+  "bugs": {
+    "url": "https://github.com/Chersquwn/leetcode/issues"
+  },
+  "homepage": "https://github.com/Chersquwn/leetcode#readme",
+  "dependencies": {
+    "axios": "^0.18.0"
+  },
+  "devDependencies": {
+    "husky": "^1.3.1"
+  }
+}

package.json

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+const axios = require('axios');
+const fs = require('fs');
+
+const API = 'https://leetcode.com/api/problems/algorithms/';
+const SOLUTION_Path = './algorithms/';
+let README_TMPL = `# LeetCode
+
+LeetCode solutions with JavaScript
+
+## LeetCode Algorithms
+
+| # | Title | Explanation | Solution | Difficulty |
+|:---:|:---:|:---:|:---:|:---:|
+`;
+
+fetchProblems()
+  .then(problems => {
+    return addSolutions(problems);
+  })
+  .then(problems => {
+    generateReadme(problems);
+  });
+
+
+function fetchProblems() {
+  const time = Date.now()
+  return axios.get(API).then(res => {
+    const { stat_status_pairs } = res.data;
+    const difficulty = ['', 'Easy', 'Medium', 'Hard'];
+    const problems = stat_status_pairs
+      .map(item => ({
+        id: item.stat.question_id,
+        title: item.stat.question__title,
+        url: `https://leetcode.com/problems/${item.stat.question__title_slug}/`,
+        difficulty: difficulty[item.difficulty.level]
+      }))
+      .sort((a, b) => b.id - a.id);
+    return problems;
+  });
+}
+
+function addSolutions(problems) {
+  const newProblems = problems.map(problem => {
+    try {
+      const files = fs.readdirSync(SOLUTION_Path + problem.title);
+
+      files.forEach(file => {
+        if (file.endsWith('js')) {
+          problem.solution = 'JavaScript';
+          problem.solutionUrl = encodeURI(
+            SOLUTION_Path + problem.title + '/' + file
+          );
+        }
+      });
+    } catch (error) {
+      console.log(error)
+    }
+
+    return problem;
+  });
+
+  return Promise.resolve(newProblems);
+}
+
+function generateReadme(problems) {
+  problems.forEach(({ id, title, url, difficulty, solution, solutionUrl }) => {
+    README_TMPL += `| ${id} | [${title}](${url}) |  | `
+
+    if (solution) {
+      README_TMPL += `[${solution}](${solutionUrl})`
+    }
+
+    README_TMPL += ` | ${difficulty} | \n`;
+  });
+
+  fs.writeFileSync('README.md', README_TMPL);
+
+  console.info('README.md generate successfully');
+}