OJ(Online judge, 在线编程测评提交代码到后台运行检查)网站一般都允许各种各样的代码提交，其中很有可能包含python3，于是决定尝试通过python3的代码执行，进行沙箱逃逸，以及绕过各种限制。
|Binary Indexed Tree / Fenwick Tree|
psql -U postgres
Some interesting flags (to see all, use
--help depending on your psql version):
-E: will describe the underlaying queries of the
\commands (cool for learning!)
-l: psql will list all databases and then exit (useful if the user you connect with doesn't has a default database, like at AWS RDS)
This post also appears on lisper.in.
Reader macros are perhaps not as famous as ordinary macros. While macros are a great way to create your own DSL, reader macros provide even greater flexibility by allowing you to create entirely new syntax on top of Lisp.
Paul Graham explains them very well in [On Lisp] (Chapter 17, Read-Macros):
The three big moments in a Lisp expression's life are read-time, compile-time, and runtime. Functions are in control at runtime. Macros give us a chance to perform transformations on programs at compile-time. ...read-macros... do their work at read-time.
|NOTE: Easier way is the X86 way, described on https://www.genymotion.com/help/desktop/faq/#google-play-services|
|Download the following ZIPs:|
|ARM Translation Installer v1.1 (http://www.mirrorcreator.com/files/0ZIO8PME/Genymotion-ARM-Translation_v1.1.zip_links)|
|Download the correct GApps for your Android version:|
|Google Apps for Android 6.0 (https://www.androidfilehost.com/?fid=24052804347835438 - benzo-gapps-M-20151011-signed-chroma-r3.zip)|
|Google Apps for Android 5.1 (https://www.androidfilehost.com/?fid=96042739161891406 - gapps-L-4-21-15.zip)|
|Google Apps for Android 5.0 (https://www.androidfilehost.com/?fid=95784891001614559 - gapps-lp-20141109-signed.zip)|
This is a quick guide on installing HTTPie for Mac OS X systems. This is also useful if you want the python package management utility
pip. An installed copy of Homebrew is a prerequisite.
brew install httpie
解决方案来自:[Apple Support Communities] (https://discussions.apple.com/thread/3275811?start=0&tstart=0)
$ sudo cp /var/run/racoon/xxx.xxx.xxx.xxx.conf /etc/racoon
$ sudo vim /etc/racoon/racoon.conf
# include "/var/run/racoon/*.conf" ;