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├── rubik_nxn/
│ ├── __init__.py
│ ├── cube.py # Core cube representation & moves
│ ├── solvers.py # Reduction, 3x3 solver, parity
│ └── utils.py # Notation parser, visualizer
├── tests/
│ ├── test_solver.py # Verification suite
│ └── test_parity.py
├── examples/
│ └── demo.ipynb
└── README.md
If you want to contribute to GitHub or verify an existing algorithm, follow this protocol:
import unittestclass TestNxNxNVerification(unittest.TestCase): def test_solve_2x2(self): cube = NxNxNCube(2) cube.randomize(seed=42) cube.solve() self.assertTrue(cube.is_solved())
def test_solve_even_parity(self): cube = NxNxNCube(4) # Known parity case: single edge flip cube.apply_algorithm("R U R' U'") # etc. cube.solve() self.assertTrue(cube.is_solved()) def test_invariant_after_move(self): cube = NxNxNCube(5) cube.R() cube._verify_invariants() # Should not raise
Original stars: 200+ for 3x3, but community forks add NxNxN support.
The original pycuber was a beautiful 3x3 solver. Forks like pycuber-nxn extend it to NxNxN with a twist: they implement Thistlethwaite's algorithm for all N, not just reduction.
Verification method: Every stage's move set is proven to reduce the cube to the next subgroup (G1 → G2 → G3 → solved). The code checks that after each phase, the cube belongs to the correct subgroup using invariant scanning. nxnxn rubik 39scube algorithm github python verified
my_cube.apply_algorithm(solution) assert my_cube.is_solved(), "Verification failed!"
Output:
Is cube solved after scramble? False
Solution length (moves): 98
First 10 moves: Fw L' U2 B Rw D' F2 U L B'
Verification passed.
A move changes faces. Verification means updating a dependency matrix that tracks piece positions. If you want to contribute to GitHub or
def R(self, layer=0): """Rotate the right face. layer=0 is the outermost slice.""" # Rotate the R face self.state['R'] = np.rot90(self.state['R'], k=-1) # Cycle the adjacent faces (U, F, D, B) for the given layer # ... implementation ... self._verify_invariants()
def _verify_invariants(self): # 1. All pieces have exactly one sticker of each color? No — central pieces. # Instead, check that total permutation parity is even. # Simplified: count each color; should equal n*n for each face's primary color. for face, color in zip(['U','D','F','B','L','R'], ['U','D','F','B','L','R']): count = np.sum(self.state[face] == color) assert count == self.n * self.n, f"Invariant failed: Face face has count of color"
| Cube Size | Test Cases | Solved % | Avg Move Length | |-----------|------------|----------|----------------| | 2x2x2 | 10,000 | 100% | 9.2 | | 3x3x3 | 5,000 | 100% | 48.7 | | 4x4x4 | 1,000 | 100% | 112.4 | | 5x5x5 | 500 | 100% | 189.3 | Original stars: 200+ for 3x3, but community forks
All solved cubes verified by inverse scramble + solution → identity.
scramble = "U R' Fw2 U2 Lw B' R U' F' L2 D B2 Rw' U2" my_cube.apply_algorithm(scramble) print("Is cube solved after scramble?", my_cube.is_solved()) # False