Merge branch 'master' of https://github.com/Gapur/leetcode

Author: Gapur

.github/CODEOWNERS

@@ -0,0 +1,17 @@
+name: Sync
+
+on:
+  push:
+    branches: [ master ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - name: Sync to Gitee
+      uses: wearerequired/git-mirror-action@master
+      env:
+          SSH_PRIVATE_KEY: ${{ secrets.GITEE_RSA_PRIVATE_KEY }}
+      with:
+          source-repo: "git@github.com:doocs/leetcode.git"
+          destination-repo: "git@gitee.com:Doocs/leetcode.git"

.github/workflows/sync.yml

@@ -1,35 +1,3 @@
-/gradle/wrapper/gradle-wrapper.properties
-##----------Android----------
-# build
-*.apk
-*.ap_
-*.dex
-*.class
-bin/
-gen/
-build/
-
-# gradle
-.gradle/
-gradle-app.setting
-!gradle-wrapper.jar
-build/
-
-local.properties
-
-##----------idea----------
-*.iml
 .idea/
-*.ipr
-*.iws
-
-# Android Studio Navigation editor temp files
-.navigation/
-
-##----------Other----------
-# osx
-*~
 .DS_Store
-gradle.properties
-
 .vscode

.gitignore

@@ -10,35 +10,49 @@
   <a href="https://github.com/doocs/leetcode/blob/master/LICENSE"><img src="https://badgen.net/github/license/doocs/leetcode?color=green" alt="LICENSE"></a><br>
   <a href="http://makeapullrequest.com"><img src="https://badgen.net/badge/PRs/welcome/cyan" alt="PRs Welcome"></a>
   <a href="https://doocs.github.io/#/?id=how-to-join"><img src="https://badgen.net/badge/organization/join%20us/cyan" alt="open-source-organization"></a>
-  <!-- <a href="#backers" alt="sponsors on Open Collective"><img src="https://opencollective.com/doocs-leetcode/backers/badge.svg" /></a> 
-  <a href="#sponsors" alt="Sponsors on Open Collective"><img src="https://opencollective.com/doocs-leetcode/sponsors/badge.svg" /></a> -->
 </p>
 
-## Introduction
-Complete [solutions](/solution) to [LeetCode problems](https://leetcode-cn.com/problemset/all/), updated daily.
+## 介绍
+本项目包含 [LeetCode](https://leetcode-cn.com/problemset/all/)、[《剑指 Offer（第 2 版）》](https://leetcode-cn.com/problemset/lcof/)、[《程序员面试金典（第 6 版）》](https://leetcode-cn.com/problemset/lcci/)等题目的相关题解。所有题解均由多种编程语言实现，包括但不限于：Java、Python、C++、JavaScript、C#、Go，日常更新。欢迎 [Star](https://github.com/doocs/leetcode) 关注本项目，获取项目最新动态。
 
-## Solution Tree
-See [SOLUTION_TREE](/solution/README.md).
+[English Version](/README_EN.md)
 
-## Contributions
-I'm looking for long-term contributors/partners to this repo! Send me [PRs](https://github.com/doocs/leetcode/pulls) if you're interested! See the following:
-- <kbd>Fork</kbd> [this repository](https://github.com/doocs/leetcode) to your own GitHub account and then <kbd>clone</kbd> it to your local machine.
-- Make some changes to your leetcode repository, then <kbd>add</kbd>, <kbd>commit</kbd> and <kbd>push</kbd> the changes to your remote GitHub repository.
-- Submit a pull request with your changes!
-- See [CONTRIBUTING](https://github.com/doocs/.github/blob/master/CONTRIBUTING.md) or [GitHub Help](https://help.github.com/en) for more details.
+## 站点
+- GitHub Pages: https://doocs.github.io/leetcode
+- Coding Pages: https://d3jc40.coding-pages.com
+
+注：若 [GitHub Pages](https://doocs.github.io/leetcode) 访问加载过慢，可访问 [Coding Pages](https://d3jc40.coding-pages.com)。
+
+## 题解
+- [LeetCode](/solution/README.md)
+- [剑指 Offer（第 2 版）](/lcof/README.md)
+- [程序员面试金典（第 6 版）](/lcci/README.md)
+
+## 维护者
+[Yang Libin](https://github.com/yanglbme): GitHub 技术社区 [@Doocs](https://github.com/doocs) 创建者；[@TheAlgorithms](https://github.com/TheAlgorithms) 组织成员。
+
+## 加入我们
+刷编程题的最大好处就是**可以锻炼解决问题的思维能力**。相信我，「如何去思考」​本身也是一项需要不断学习和练习的技能。非常感谢前微软工程师、现蚂蚁金服技术专家 [@kfstorm](https://github.com/kfstorm) 贡献了本项目的所有 [C# 题解](https://github.com/doocs/leetcode/pull/245)。
+
+如果你对本项目感兴趣，并且希望加入我们刷题大军，欢迎随时提交 [PR](https://github.com/doocs/leetcode/pulls)。请参考如下步骤：
+
+- 将[本项目](https://github.com/doocs/leetcode) <kbd>Fork</kbd> 到你的个人 GitHub 帐户，然后 <kbd>clone</kbd> 到你的本地机器；
+- 对项目做出一些变更，然后使用 git <kbd>add</kbd>、<kbd>commit</kbd>、<kbd>push</kbd> 等命令将你的变更提交到你的远程 GitHub 仓库；
+- 将你的变更以 PR 的形式提交过来，项目的维护人员会在第一时间对你的变更进行 review！
+- 你也可以参考 [GitHub 帮助文档](https://help.github.com/cn) 了解更多细节。
 
 <p align="center">
   <a href="https://github.com/doocs/leetcode"><img src="./img/how-to-contribute.png" alt="how-to-contribute"></a>
 </p>
 
-You can also contribute to [doocs/leetcode](https://github.com/doocs/leetcode) using [Gitpod.io](https://www.gitpod.io), a free online dev environment with a single click.
+[Gitpod.io](https://www.gitpod.io) 是一个免费的在线开发环境，你也可以使用它参与本项目。
 
 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/#https://github.com/doocs/leetcode)
 
-## Contributors
-This project exists thanks to all the people who contribute. 
+## 贡献者
+非常感谢以下所有朋友对本项目的贡献，你们是最可爱的人！
 
-<a href="https://opencollective.com/doocs-leetcode/contributors.svg?width=890&button=true"><img src="https://opencollective.com/doocs-leetcode/contributors.svg?width=890&button=false" /></a>
+<a href="https://opencollective.com/doocs-leetcode/contributors.svg?width=890&button=true"><img src="https://opencollective.com/doocs-leetcode/contributors.svg?width=1200&button=false" /></a>
 
-## License
-<a rel="license" href="https://github.com/doocs/leetcode/blob/master/LICENSE"><img alt="Creative Commons License" style="border-width:0" src="./img/cc-by-sa-88x31.png" /></a><br />This work is licensed under a <a rel="license" href="http://creativecommons.org/licenses/by-sa/4.0/">Creative Commons Attribution-ShareAlike 4.0 International License</a>.
+## 许可证
+<a rel="license" href="https://github.com/doocs/leetcode/blob/master/LICENSE"><img alt="Creative Commons License" style="border-width:0" src="./img/cc-by-sa-88x31.png" /></a><br /><a rel="license" href="http://creativecommons.org/licenses/by-sa/4.0/">知识共享 版权归属-相同方式共享 4.0 国际 公共许可证</a>

README.md

@@ -0,0 +1,54 @@
+<p align="center">
+  <a href="https://github.com/doocs/leetcode"><img src="./img/leetcode-doocs.png" alt="LeetCode-GitHub-Doocs"></a>
+</p>
+
+<p align="center">
+  <a href="https://github.com/doocs/leetcode"><img src="https://badgen.net/badge/langs/Java,C++,Python,JavaScript,Go,.../green?list=1" alt="languages"></a>
+  <a href="https://github.com/doocs/leetcode/stargazers"><img src="https://badgen.net/github/stars/doocs/leetcode" alt="stars"></a>
+  <a href="https://github.com/doocs/leetcode/issues"><img src="https://badgen.net/github/open-issues/doocs/leetcode" alt="issues"></a>
+  <a href="https://github.com/doocs/leetcode/network/members"><img src="https://img.shields.io/github/forks/doocs/leetcode.svg" alt="forks"></a>
+  <a href="https://github.com/doocs/leetcode/blob/master/LICENSE"><img src="https://badgen.net/github/license/doocs/leetcode?color=green" alt="LICENSE"></a><br>
+  <a href="http://makeapullrequest.com"><img src="https://badgen.net/badge/PRs/welcome/cyan" alt="PRs Welcome"></a>
+  <a href="https://doocs.github.io/#/?id=how-to-join"><img src="https://badgen.net/badge/organization/join%20us/cyan" alt="open-source-organization"></a>
+</p>
+
+## Introduction
+Complete solutions to [LeetCode](https://leetcode-cn.com/problemset/all/), [LCOF](https://leetcode-cn.com/problemset/lcof/) and [LCCI](https://leetcode-cn.com/problemset/lcci/) problems, updated daily.
+
+[中文文档](/README.md)
+
+## Sites
+- GitHub Pages: https://doocs.github.io/leetcode
+- Coding Pages: https://d3jc40.coding-pages.com
+
+## Solutions
+- [LeetCode](/solution/README_EN.md)
+- [LCOF: *Coding Interviews, 2nd Edition*](/lcof/README_EN.md)
+- [LCCI: *Cracking the Coding Interview, 6th Edition*](/lcci/README_EN.md)
+
+## Maintainer
+[Yang Libin](https://github.com/yanglbme): Creator of [@Doocs](https://github.com/doocs) technical community; member of [@TheAlgorithms](https://github.com/TheAlgorithms) organization.
+
+## Contributions
+I'm looking for long-term contributors/partners to this repo! Send me [PRs](https://github.com/doocs/leetcode/pulls) if you're interested! See the following:
+
+- <kbd>Fork</kbd> [this repository](https://github.com/doocs/leetcode) to your own GitHub account and then <kbd>clone</kbd> it to your local machine.
+- Make some changes to your leetcode repository, then <kbd>add</kbd>, <kbd>commit</kbd> and <kbd>push</kbd> the changes to your remote GitHub repository.
+- Submit a pull request with your changes!
+- See [CONTRIBUTING](https://github.com/doocs/.github/blob/master/CONTRIBUTING.md) or [GitHub Help](https://help.github.com/en) for more details.
+
+<p align="center">
+  <a href="https://github.com/doocs/leetcode"><img src="./img/how-to-contribute.png" alt="how-to-contribute"></a>
+</p>
+
+You can also contribute to [doocs/leetcode](https://github.com/doocs/leetcode) using [Gitpod.io](https://www.gitpod.io), a free online dev environment with a single click.
+
+[![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/#https://github.com/doocs/leetcode)
+
+## Contributors
+This project exists thanks to all the people who contribute. 
+
+<a href="https://opencollective.com/doocs-leetcode/contributors.svg?width=890&button=true"><img src="https://opencollective.com/doocs-leetcode/contributors.svg?width=1200&button=false" /></a>
+
+## License
+<a rel="license" href="https://github.com/doocs/leetcode/blob/master/LICENSE"><img alt="Creative Commons License" style="border-width:0" src="./img/cc-by-sa-88x31.png" /></a><br />This work is licensed under a <a rel="license" href="http://creativecommons.org/licenses/by-sa/4.0/">Creative Commons Attribution-ShareAlike 4.0 International License</a>.

README_EN.md

@@ -0,0 +1,90 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <meta charset="UTF-8">
+  <title>LeetCode、剑指Offer、程序员面试金典题解</title>
+  <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1" />
+  <meta name="keywords" content="doc,docs,doocs,documentation,github,gitee,coding,pages,leetcode,coding-interview,cracking-the-coding-interview,yanglbme">
+  <meta name="description" content="LeetCode、剑指Offer、程序员面试金典题解">
+  <meta name="viewport" content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
+  <link rel="stylesheet" href="//unpkg.com/docsify/lib/themes/vue.css">
+  <link rel="stylesheet" href="//unpkg.com/docsify-dark-mode@0.6.1/dist/style.css" />
+  <link rel="icon" type="image/png" sizes="32x32" href="img/favicon-32x32.png">
+  <link rel="icon" type="image/png" sizes="16x16" href="img/favicon-16x16.png">
+</head>
+
+<body>
+  <div id="app">本系列知识由 Doocs 开源社区原创发布</div>
+  <script>
+    window.$docsify = {
+      name: 'leetcode',
+      logo: '/img/doocs-leetcode.png',
+      search: [
+        '/','/solution/','/lcof/','lcci/'
+      ],
+      auto2top: true,
+      loadSidebar: 'summary.md',
+      alias: {
+        '/lcci/.*/summary.md': '/lcci/summary.md',
+        '/lcof/.*/summary.md': '/lcof/summary.md',
+        '/solution/.*/summary.md': '/solution/summary.md'
+      },
+      pagination: {
+        previousText: '上一题',
+        nextText: '下一题',
+        crossChapter: true,
+        crossChapterText: true
+      },
+      darkMode: {
+        light: {
+          toggleBtnBg: '#42b983'
+        }
+      },
+      plugins: [
+        function (hook) {
+          var footer = [
+            '<hr/>',
+            '<footer>',
+            '<span>Copyright © 2018-2020 <a href="https://github.com/doocs" target="_blank">Doocs</a>. All rights reserved.',
+            '</footer>'
+          ].join('')
+
+          hook.afterEach(function (html) {
+            return html + footer
+          })
+        },
+        function (hook, vm) {
+          hook.beforeEach(function (html) {
+            if (/githubusercontent\.com/.test(vm.route.file)) {
+              url = vm.route.file
+                .replace('raw.githubusercontent.com', 'github.com')
+                .replace(/\/master/, '/blob/master')
+            } else {
+              url = 'https://github.com/doocs/leetcode/blob/master/' + vm.route.file
+            }
+            var editHtml = '[:memo: Edit on GitHub](' + url + ')\n'
+            return editHtml + html
+          })
+        },
+      ]
+    }
+  </script>
+  <script src="//unpkg.com/docsify/lib/docsify.min.js"></script>
+  <script src="//unpkg.com/prismjs/components/prism-c.min.js"></script>
+  <script src="//unpkg.com/prismjs/components/prism-go.min.js"></script>
+  <script src="//unpkg.com/prismjs/components/prism-sql.min.js"></script>
+  <script src="//unpkg.com/prismjs/components/prism-bash.min.js"></script>
+  <script src="//unpkg.com/prismjs/components/prism-cpp.min.js"></script>
+  <script src="//unpkg.com/prismjs/components/prism-json.min.js"></script>
+  <script src="//unpkg.com/prismjs/components/prism-java.min.js"></script>
+  <script src="//unpkg.com/prismjs/components/prism-csharp.min.js"></script>
+  <script src="//unpkg.com/prismjs/components/prism-javascript.min.js"></script>
+  <script src="//unpkg.com/prismjs/components/prism-python.min.js"></script>
+  <script src="//unpkg.com/docsify-copy-code"></script>
+  <script src="//unpkg.com/docsify/lib/plugins/search.js"></script>
+  <script src="//unpkg.com/docsify/lib/plugins/emoji.js"></script>
+  <script src="//unpkg.com/docsify/lib/plugins/zoom-image.js"></script>
+  <script src="//unpkg.com/docsify-dark-mode@0.6.1/dist/index.js"></script>
+  <script src="//unpkg.com/docsify-pagination/dist/docsify-pagination.min.js"></script>
+</body>
+</html>

img/favicon-16x16.png

@@ -0,0 +1,63 @@
+# [面试题 01.01. 判定字符是否唯一](https://leetcode-cn.com/problems/is-unique-lcci)
+
+## 题目描述
+<!-- 这里写题目描述 -->
+<p>实现一个算法，确定一个字符串 <code>s</code> 的所有字符是否全都不同。</p>
+
+<p><strong>示例 1：</strong></p>
+
+<pre><strong>输入:</strong> <code>s</code> = &quot;leetcode&quot;
+<strong>输出:</strong> false 
+</pre>
+
+<p><strong>示例 2：</strong></p>
+
+<pre><strong>输入:</strong> <code>s</code> = &quot;abc&quot;
+<strong>输出:</strong> true
+</pre>
+
+<p><strong>限制：</strong></p>
+<ul>
+	<li><code>0 <= len(s) <= 100 </code></li>
+	<li>如果你不使用额外的数据结构，会很加分。</li>
+</ul>
+    
+
+## 解法
+<!-- 这里可写通用的实现逻辑 -->
+
+
+### Python3
+<!-- 这里可写当前语言的特殊实现逻辑 -->
+
+```python
+class Solution:
+    def isUnique(self, astr: str) -> bool:
+        sets = set(astr)
+        return len(sets) == len(astr)
+```
+
+### Java
+<!-- 这里可写当前语言的特殊实现逻辑 -->
+
+```java
+class Solution {
+    public boolean isUnique(String astr) {
+        char[] chars = astr.toCharArray();
+        int len = chars.length;
+        for (int i = 0; i < len - 1; ++i) {
+            for (int j = i + 1; j < len; ++j) {
+                if (chars[i] == chars[j]) {
+                    return false;
+                }
+            }
+        }
+        return true;
+    }
+}
+```
+
+### ...
+```
+
+```