Last update: 27.07.2015

Computing Environment

During the Helvetic Coding Contest, you will use a computer environment based on Linux to access the problems, write and test your solutions. This page contains information about the software and hardware, and allows you to try out the system.

At the registration, you have the option to bring your own laptop. This has a number of benefits and conditions:

  • You will have a keyboard/mouse/hardware that you already know well.
  • Your hardware might be newer than the machines in the computer rooms.
  • Your laptop must be able to boot from USB, and you must try out the system in advance (see below)
If you bring your own laptop, it is crucial that you try out the system beforehand! Otherwise, expect trouble...

Trying it out

You can download an image of the system that we'll use during the competition, and try it out at home:

  1. Download the polyprog-live image (825 MB).
  2. Copy the image to a USB stick.
    On Linux, you can use cp 2015hc2.iso /dev/sdb
    On Mac, the command is dd if=2015hc2.iso of=/dev/rdisk2 bs=1m
    On Windows, Rufus can do this.
    Warning: replace sdb or rdisk2 by the device that corresponds to your USB drive. All data on that device will be erased.
  3. Re-boot the computer from the USB stick. The stick should boot on any modern 64-bit system. You might have to enable booting from USB in the BIOS, though.
  4. Send any comments to jonas (at

Frequently Asked Questions

How do I change my keyboard layout?
For Swiss French, use the setxkbmap ch fr command in a terminal.
Things on the screen look extremely small...
You can scale the display using xrandr --output eDP1 --scale 0.75x0.75. Replace eDP1 by the name of your screen (it's printed when you run xrandr without parameters).
How to get network access?
The live system tries to connect to the EPFL network automatically. If you're at EPFL and it doesn't work, please email jonas at immediately. If you're not at EPFL, please run ip link in a terminal. If it shows a wlan0 interface, your network card has been recognized and things will likely work at the contest. Otherwise, please email jonas at
My computer doesn't boot from USB stick...
Try disabling UEFI in the BIOS.
Can we also bring our own keyboard, screen, mouse, ...
Yes, sure!
Can we use two screens?
No, sorry... this would give an unfair advantage to your team.
Do I need to install anything?
No, the system runs as a live system and does not modify your computer.
What if the system crashes during the contest?
We regularly create backups of your files, and can restore them if your computer crashes. Note that we only backup files if you save them, though.
Can I run this inside a virtual machine during the contest?
No, sorry (that would make it too easy to cheat during the competition).
Does it work on a Mac?
We tested it on a 13-inch MacBook... try the following:
  • Prepare the USB stick. On mac, it’s something like dd if=2015hc2.iso of=/dev/rdisk2 bs=1m. You can use the Disk Utility to see the device name of your USB stick.
  • Insert the USB stick into the computer
  • Reboot, pressing the ALT key during boot
  • Select the USB drive (it’s probably labeled “Windows”)


The contest will take place on your laptop, or on computers with the following specification:
  • Hardware:
    CPU:Intel Core i7-4770 CPU @ 3.4GHz
    RAM:8 GB
    Keyboard:Standard Swiss-French keyboard
     (keyboard layout can be changed in the desktop environment)
    Mouse:Standard 2 button mouse with scroll wheel.
  • Software:
    OS:Linux (distribution: Debian live)
    Editors:gvim, emacs, geany, scite, sublime text 2, eclipse
    Debugger:gdb, ddd
    C compiler:gcc 4.9.2
    C++ compiler:g++ 4.9.2
    Java compiler:OpenJDK 1.7.0
    Scala compiler:Scala 2.11.6
    Python:Version 2.7.9 and 3.4.2
    Ruby:Version 2.1.5