Microsoft’s Quantum team is excited to announce the Q# Coding Contest – Winter 2019! In this contest you can put your quantum programming skills to the test, solving quantum computing tasks in Q#. Winners will receive a Microsoft Quantum T-shirt!

Quantum computing is a radically different computing paradigm compared to classical computing. Indeed, it is so different that some tasks that are believed to be classically intractable (such as factoring integers or simulating physical systems) can be performed efficiently on a quantum computer. In 2017 Microsoft introduced the Quantum Development Kit which includes the Q# programming language. Q# can be used with Visual Studio, Visual Studio Code or the command line, on Windows, macOS, and Linux.

In summer of 2018 we hosted the first quantum programming contest, which included problems on introductory topics in quantum computing: superposition, measurement, quantum oracles and simple algorithms. This contest will offer harder problems on some of these topics as well as introduce some new topics.

The contest will run from March 1 to March 4. The rules of the contest are:

• The contest will have 12 tasks of various complexity levels.
• To solve each task, you will write Q# code to implement the described transformation on the given set of qubits or to perform a more challenging task. Solutions are accepted in Q# only.
• The solution is correct if it passes all tests from a predefined test set. You will know whether the solution is correct soon after submitting it.
• Participants are ranked according to the number of correctly solved tasks.
• Ties are resolved based on lowest penalty time for all tasks, which is computed as the latest submission time (the time since the start of the contest) for any of the correctly solved tasks. An extra penalty of 20 minutes is added for each failed submission on solved tasks (i.e., if you never solve the task, you will not be penalized for trying that task).
• The top 50 ranked participants will receive a Microsoft Quantum T-shirt.
• NO PURCHASE NECESSARY. Must be 16 years of age or older. Game ends 3/4/19. For details, see Official Rules.

We will offer a warmup round the weekend before the contest, from February 22 to February 25. Participation in the warmup round is entirely optional. The warmup round includes simpler tasks on the topics covered in the main contest and gives you an opportunity to get familiar with the contest environment and submission system beforehand, as well as refresh or learn the basics of quantum computing and the Q# programming language. During the warmup round everybody is encouraged to discuss the tasks and the solutions. Once the warmup round is over, we will publish the editorials explaining both the quantum computing logic behind the solution and the Q# implementation on the contest page.

Another great way to prepare for the contest is to solve some of the Quantum Katas. They offer problems on a variety of quantum programming topics, and they are very similar to the ones used in the contest. In fact, the participants of the summer Q# contest will recognize the contest problems in some of the kata tasks :-)

Good luck! We hope you enjoy the contest!

For first time Codeforces users:

1. Create user account here.
2. Register for the warmup round here.
3. Register for the contest here.
4. Once the warmup round starts on February 22, access the problems here.
5. Once the contest starts on March 1, access the problems here.

Quantum computing and Q# materials:

• Quantum Computing: Lecture Notes by Ronald de Wolf.
• A collection of awesome quantum computing learning resources, including MOOCs and books.
• Q# installation instructions and documentation.
• Quantum Katas — Q# programming exercises.
• Q# Language Quick Reference.

Note that this contest will use Q# 0.4, while the previous contest used Q# 0.2. A lot of code written in 0.2 will still work in 0.4; for details on breaking changes and new features please see release notes.