Competitive Programming Library for Vim

An useful CP library on Vim editor.

I mainly use it for fast programming, and also for handling tricky codes like cycle detection or SCC.

I made it to use by myself. The readability would be poor. I am planning to fix it to be more readable to anyone.

I upload this library to convince that these codes are all written by myself before the contest.

Codeforces or e.t.c.

Korean Explanation: My Blog Link

Computer Environment

OS: Ubuntu 18.04.4 LTS
Compiler: g++ 7.4.0 with C++17
Programming: Vim 8.0 on Ubuntu Bash Shell (CUI)
- Plugin 'VundleVim/Vundle.vim' is installed (But don't need to use on C++)
  - Plugin 'The-NERD-tree' is useful.
'vimrc, cvimrc' inside /vim is located in the home directory, as named '.vimrc, .cvimrc'

Programming Environment

Codes, I/O Files Directory Settings

Every C++ programmings are done inside the directory ~/c.
- Type mkdir ~/c on your shell to create.
Default input, output files are ~/c/input.txt and ~/c/output.txt.
- Type touch ~/c/input.txt and touch ~/c/output.txt to make them.
Every .cpp library codes inside /library on this repository will be located in ~/c/library/.
- Type mkdir ~/c/library and copy & paste every .cpp code in this repository to the target folder.

In my case, I use the following file hierarchy.

home
├── .vimrc
├── .cvimrc
└── c
    ├── A.cpp
    ├── B.cpp
    ├── C.cpp
    ├── D.cpp
    ├── E.cpp
    ├── F.cpp
    ├── G.cpp                         // A to G: Codeforces Problems
    ├── input.txt                     // input file
    ├── output.txt                    // output file
    ├── X.cpp                         // main codes
    └── library                       // library folder
        ├── aho_corasick.cpp
        ├── base.cpp
        ├── binary_indexed_tree.cpp
        ├── bipartite_matching.cpp
        ├── dinic.cpp
        ├── fast_fourier.cpp
        ├── fenwick_tree.cpp
        ├── gauss_elim.cpp
        └── ...

Programming Ways

I mainly use Ubuntu Bash Shell and CUI Vim on the Terminal.
Access the programming file on the home directory. For example,
```
$ cd ~
$ vim c/X.cpp
```
Press [Ctrl + p] to show I/O files on the right side of the window.
Focus on the main programming file window and press [Ctrl + o] to close I/O files.
Type :Base to load ~/c/library/base.cpp file.
- You can edit the base file for your own preference.
Press [Ctrl + F5] [Enter] to compile the .cpp file.
Press [Ctrl + F6] [Enter] to run the compiled file reads input from input.txt and outputs output.txt.
Press [Ctrl + F7] [Enter] to run the compiled file on the Bash Shell.
Other key binding are easily implemented on the cvimrc file.

Library Loading

Make sure that your cursor is located in the global variable declaration area. (Not inside a function.)
Press [Leader + l] to see what we have inside the ~/c/library folder.
- The default Leader key is \ (backslash).
If you want to load fast_fourier.cpp, then type fast_fourier correctly on Vim(chop .cpp part), and press to exit the Insert mode. And press [Leader + l].
- Before pressing [Leader + l].
- After pressing [Leader + l].
- Now you can see the folded 60 lines on your file.
- A folded lines can be unfolded by pressing [Spacebar]. It can be unfolded by typing [zc].

Customizing and Creating a Library Code

There are marks on every library code. For example, on union_find.cpp,
- You might see that the class union_find is wrapped by the marks;
  - //////// ---- Woosung Song's Source Code ---- ////////
- When you press [Leader + l], the content between the two marks is loaded.
The mark can be edited on .cvimrc. It is written with Vim-Python script. But I don't recommend to do that because you will have to do so many things to edit them all..

Creating a Library Code

The common structure for every library code is that,
- It begins with
```
#include <bits/stdc++.h>

using namespace std;
```
- Has the start mark with (You can insert it by pressing [Leader + m].)
```
//////// ---- Woosung Song's Source Code ---- ////////
```
- Library content wrapped by #ifndef.
```
#ifndef UNION_FIND_DEFINED
class union_find {
    ...
};
#endif

#define UNION_FIND_DEFINED
```
  - This is crucial to avoid the method overloading problem. (Which is not supported on C++.)
- The end mark with (You can insert it by pressing [Leader + m].)
```
//////// ---- Woosung Song's Source Code ---- ////////
```
- (Optional) The test code.
```
int main() {
    union_find uf(10);
    // ... test code ...
}
```
  - The test code will not be added if you import your library. (Since it is not wrapped inside the marks.)
You can easily add your own library by just keeping the above basic structure.

lego0901/CP_Library