Running Code Locally
Author: Many
Contributors: Benjamin Qi, Hankai Zhang, Anthony Wang, Nathan Wang, Nathan Chen, Owen Wang, Shourya Bansal, Dong Liu
Options for running your language of choice locally.
Prerequisites
If you're just starting out, it's easier to begin by running code online and worry about running locally later. You can find more information about running code online here.
Resources | ||||
---|---|---|---|---|
IOI | for reference, software you can use at IOI |
Code Editors vs IDEs
First, you'll need to decide whether to use a code editor such as Sublime Text or an integrated development environment (IDE) such as Visual Studio. An IDE provides many features beyond just a code editor, though as you won't need most of them for competitive programming, a code editor alone may suit your needs. More Info
Which code editor or IDE should I use?
It depends on your personal preference. Try multiple and see which one you like best.
Using an IDE/Editor
If you've only run code online before, it's probably easiest to start by installing Visual Studio Code. Please let us know if you have trouble with this process!
Resources | ||||
---|---|---|---|---|
Microsoft | ||||
Jetbrains | Requires a license, but free for students. | |||
Geany | Lightweight, frequently used at IOI. | |||
Code::Blocks | Windows & Linux. Apparently was unstable at IOI. | |||
Apple | Mac only. |
Using the Command Line
Alternatively, you can edit your code with an editor of your choice and run your C++ programs via the command line (e.g., Terminal on Mac). See this module for information about installing, compiling, and running C++ from the command line.
Resources | ||||
---|---|---|---|---|
Fast, lightweight, easy to use. Unlimited free evaluation period, though it will repeatedly ask you to purchase a license. | ||||
Classic text editor, usually preinstalled on Linux. Also see Neovim, MacVim. Probably the easiest way to print syntax-highlighted code on Mac, see this post. |
Sublime Text Notes (Ben)
<bits/stdc++.h>
Including If you have installed g++
as described
here, you can use
#include <bits/stdc++.h>
in place of separately including libraries.
Usage
This is usable with
GCC. However, Mac OS X
uses Clang while Windows uses
Microsoft Visual C++ (MVSC)
by default. <bits/stdc++.h>
is not a standard header file, so it will not
work with the latter two. This is one of the reasons why you should not use
<bits/stdc++.h>
outside of competitive programming.
Resources | ||||
---|---|---|---|---|
SO | wow, people are really mad about this! | |||
SO |
<bits/stdc++.h>
Without Installing g++
Using If you installed Clang on Mac, then you can download stdc++.h
from
here
and move it into a folder named bits
that is located in the same directory as
where all other C++ header files are located.
Resources | ||||
---|---|---|---|---|
SO | solutions that may or may not work |
<bits/stdc++.h>
Precompiling Including <bits/stdc++.h>
may significantly slow down compilation time. Using
this trick usually speeds up compilation time to less than a second.
Resources | ||||
---|---|---|---|---|
CF |
Find out where
bits/stdc++.h
is located on your machine. To do so, compile your C++ filefile.cpp
that includesbits/stdc++.h
with the following command.g++ -H file.cpp
This will generate a list of included libraries. You should see a path of the form
/path_to/bits/stdc++.h
near the top of the list.Precompile the header:
g++ -add-flags-here /path_to/bits/stdc++.h
where
-add-flags-here
includes the compilation flags you normally use (ex.-std=c++17 -O2
)Recompile your C++ file. Should be faster this time since the precompiled header will be used.
g++ -add-flags-here -Winvalid-pch file.cpp
The
-Winvalid-pch
will warn you if the precompiled header is not used. For example, if I precompiledstdc++.h
with-std=c++17
but I compiled my C++ program with-std=c++11 -Winvalid-pch
, I would get a warning such as the following:file.cpp:1:25: warning: bits/stdc++.h.gch: not used because `__cpp_nontype_template_parameter_auto' not defined [-Winvalid-pch] 1 | #include "bits/stdc++.h" | ^
Module Progress:
Join the USACO Forum!
Stuck on a problem, or don't understand a module? Join the USACO Forum and get help from other competitive programmers!