Verifier

The verifier checks your file and computes its score. The server runs the same code on every submission.

Download the bundle, extract it and run these commands from its folder (the one holding verifiers/). The bundle includes an accepted example file.

python3 -m pip install -r requirements.txt
python3 -I verifiers/run_one.py emitter grid-8x8 example/grid-8x8.json

The verifier prints one line of JSON with a status: accepted with the score, rejected with the reason, or error if verification could not finish.

Files

File	Role
run_one.py	Runs the verifier
common.py	Shared helpers
emitter.py	Validates submissions for this problem

How verification works

The verifier replays your operations on an exact stabilizer tableau. Measurement outcomes are kept as symbols, so every sign in the final state is an exact formula in the outcomes. The verifier then checks that each stabilizer of the target graph state, with identity on the emitters, has sign +1 for every combination of outcomes. That proves the photons end in exactly the target state, disentangled from the emitters, in every run. QArena also reruns a second, independently written program with a different algorithm on the current records; it is not part of the download. During development it was also compared with a program that follows every outcome with explicit state vectors on small cases.