Map coloring with 2 bits?
Hello, I have modified the map coloring demo (https://docs.ocean.dwavesys.com/en/latest/examples/map_coloring.html) to encode the colors using two bits instead of four. The constraints are the following:
def ab_not_equal_cd(a, b, c, d):
return a != c or b != d
for neighbor in neighbors:
v, u = neighbor
variables = [v+'0',v+'1', u+'0',u+'1']
Here is the complete code: https://github.com/Virtual-X/bin-quad-model/blob/master/mapcoloring2.py
The CSP has less variables and less constraints, and the BQM is smaller than the original. Nonetheless, the qpu is not able to solve it, even with a lot of samples, while the SimulatedAnnealingSampler solves it consistently. Are there requirements for the constraints that are no longer respected?