Hướng dẫn và chia sẻ lời giải cho các problems trên vn.spoj.com.

• Make sure you have Ruby install in your computer, if not

sudo apt install ruby ruby-dev

• Install jekyll theme here or simply type

gem install bundler jekyll

• Install packages in gem. You'll be required password to install packages.

bundle install

• If you get error requiring "Make sure that gem install ...", please execute the command with sudo. Example, on OSX or Linux, maybe you get error:

An error occurred while installing nokogiri (1.6.8.1), and Bundler cannot continue. Make sure that gem install nokogiri -v '1.6.8.1' --source 'https://rubygems.org/' succeeds before bundling.

In case, you should run

# use sudo for permission
sudo gem install nokogiri -v '1.6.8.1' --source 'https://rubygems.org/'

• Serve jekyll server on localhost, and open http://localhost:4000/ to view the site.

bundle exec jekyll serve
# or use npm cli if you've install npm
npm start
# or use yarn instead of npm
yarn start

• If you get this error, you will need to install node.js.

jekyll 3.3.1 | Error: Could not find a JavaScript runtime. See https://github.com/rails/execjs for a list of available runtimes.

sudo apt-get install nodejs

If you contribute for the project, you maybe have some solution files or tutorial for problems.

The solution files (source code) should be in the repository https://github.com/vnspoj/solution. You will add your files which name is formatted as [problem_code].cpp or [problem_code].java in directory src/*.

Example, if the problem you solved is NKCITY (the problem url will be https://vn.spoj.com/problems/NKCITY/), then your solution file is NKCITY.cpp or NKCITY.java, and it'll be added to src, the path is src/NKCITY.cpp (or .java). And the file will be served staticly at https://vnspoj.github.io/solution/src/NKCITY.cpp

If you have multiple solutions for a problem, example such as NKCITY.cpp and NKCITY_v2.cpp or NKCITY.java, you can add to solution repository and the src value is array of filename, such as src: [NKCITY.cpp, NKCITY_v1.cpp, NKCITY.java].

The tutorial should be in this repository https://github.com/vnspoj/vnspoj.github.io. Open directory _posts and add new file markdown with extension .md or .markdown, which name is formatted as yyyy-mm-dd-[problem_code].md (or .markdown), with yyyy-mm-dd is year, month, date you write the tutorial and [problem_code] as above.

In the new file, the structure should be:

---
layout: post
title:  "NKCITY - Xây dựng thành phố"
categories: [mst, kruskal]
code: NKCITY
src: NKCITY.cpp
---

[Your content here]

In the above file, you should change the title, categories, code and src, with src is name of file you publish in the repository solution.

If you need static files (such as iamge, pdf, or bla bla), you can add in the directory static, and the url becomes https://vnspoj.github.io/static/[path/to/your/file]

• Add new file in category as the others in the directory.
• In directory _posts/tips, add new file as the others.

If in post you need use math type, you should have use_math: true in top file, such as:

---
layout: post
title:  "SPSEQ - Sequences"
categories: [dp, lis]
code: SPSEQ
src: SPSEQ.cpp
use_math: true
---

For inline math type:

That is inline:  \\( 1/x^{n} \\)

For block math type:

That is block \\[ \frac{1}{n^{2}} \\]