game2.py

from qiskit import QuantumCircuit
from qiskit.quantum_info import Statevector

def run_quantum_level(qubits, target_room, player_moves):
    """
    qubits: Number of qubits (2 or 3)
    target_room: The binary string to find (e.g., "101")
    player_moves: List of gates (e.g., ["X1", "CCZ", "X1"])
    """
    qc = QuantumCircuit(qubits)
    
    # 1. INITIAL SUPERPOSITION (The 'Start' of the maze)
    qc.h(range(qubits))
    qc.barrier()
    
    # 2. THE PLAYER'S ORACLE (The 'Lock')
    # Goal: Flip the sign of the target_room
    for gate in player_moves:
        if gate == 'X0': qc.x(0)
        if gate == 'X1': qc.x(1)
        if gate == 'X2': qc.x(2)
        
        # Select the right 'Lock' gate for the level
        if gate == 'CZ' and qubits == 2: qc.cz(0, 1)
        if gate == 'CCZ' and qubits == 3: qc.ccz(0, 1, 2)
    qc.barrier()
    
    # 3. THE DIFFUSER (The 'Amplifier')
    # This is the universal part that makes the marked room 'bright'
    qc.h(range(qubits))
    qc.x(range(qubits))
    if qubits == 2:
        qc.cz(0, 1)
    else:
        qc.h(qubits-1)
        qc.mcx(list(range(qubits-1)), qubits-1)
        qc.h(qubits-1)
    qc.x(range(qubits))
    qc.h(range(qubits))
    
    # 4. MEASURING THE OUTCOME
    state = Statevector.from_instruction(qc)
    probs = state.probabilities_dict()
    
    # In Qiskit, we need to handle the bit-string ordering correctly
    # Reversed because Qiskit uses Little Endian (q2 q1 q0)
    win_prob = probs.get(target_room[::-1], 0) 
    
    return win_prob, probs

# --- THE GAME LEVELS ---

# LEVEL 1: Target 11 (No X gates needed)
# Correct: ['CZ']
prob1, _ = run_quantum_level(2, "11", ["CZ"])

# LEVEL 2: Target 01 (Must flip Qubit 1)
# Correct: ['X1', 'CZ', 'X1']
prob2, _ = run_quantum_level(2, "01", ["X1", "CZ", "X1"])

# LEVEL 3: Target 101 (Must flip Qubit 1)
# Correct: ['X1', 'CCZ', 'X1']
prob3, _ = run_quantum_level(3, "101", ["X1", "CCZ", "X1"])