An Inside Look at the First Quantum Computing Challenge

By in Community Stories February 13, 2019

Topcoder and TC3 (premier partner in Japan) have partnered with Fujitsu and their latest system, Digital Annealer (DA), launched the first learning challenge on February 1, 2019.

The first educational challenge was to solve one of the hardest sudoku using quantum annealing.

The goal of this educational challenge on Topcoder was to learn the basics of Digital Annealer API and how to solve problems using the API in Digital Annealer (the quantum annealing style) by solving the sudoku.

As part of this challenge, the details are provided on how to turn the Sudoku problem into the QUBO formulation.

The challenge explained “Creating Objective Function” here.

The “Creating Objective Function” included the below steps:

  • Define Solution Model
  • Define the constraints
  • Transform into the QUBO formulation
  • The final objective function

Coding in Python:

The step-by-step instructions to code in python have been provided here.

The steps need to be followed sequentially and there is one TODO which competitors had to complete the code.

def build_row_rule():
   rule = BinaryQuadraticPolynomial(N * N * N)
   # TODO
   return rule.finalize()

The code which has to be written in this TODO is quite similar to the column rule from Step 2.

    for k in range(N):
       for i in range(N):
           for j1 in range(N):
               var1 = get_variable_id(N, i, j1, k)
               for j2 in range(N):
                   var2 = get_variable_id(N, i, j2, k)
                   rule.add_coef(var1, var2, 1)
               rule.add_coef(var1, var1, -2) # this is -2 * x_{var1}

Hope it helps in getting started with the Quantum Computing Challenge Series.

Upcoming Challenge #2:

Compared to the first challenge, which is more straightforward and simple, the second challenge is going to be more exciting and fun.

In the upcoming second challenge, the key formulae in the instructions will be hidden and gradually expose them over time. So, it sort of feels like playing a game.

The members who will be able to solve the task without any hints will earn the advantage and potentially win money, if they can’t they’ll will gradually see all the hidden pieces.

Find the next challenge here and get ready for it to launch on Friday.

See more about the challenge series here.

At Topcoder we pride ourselves on continuously innovating and doing our very best to present you, our community, with the most opportunities to learn new skills and earn good money.

Thank you and best of luck competing!