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 ftprep color17-t2 example/color17-t2.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
ftprep.py	Validates submissions for this problem

How verification works

The verifier simulates the noiseless circuit once with measurement-dependent signs, which covers every measurement outcome, and proves that every noiseless run is accepted and outputs exactly |0⟩ of the code. It then checks every placement of one fault, and for t = 2 every pair of faults at distinct operations (all 225 Pauli pairs for two CNOTs), using exact GF(2) arithmetic: an accepted event must leave an error whose X part and Z part each reduce, modulo the state's stabilizers, to weight at most the number of faults. The acceptance probability bound and the cost are exact fractions. A second, independently written program (a stabilizer-tableau simulation with fault-by-fault propagation) agreed with the verifier on every test case and baseline, and QArena's record audit reruns it on the current records (it is not part of the download).