Thuật toán Quantum Computing

# Grover Algorithm Implementation
from qiskit import QuantumCircuit, QuantumRegister, ClassicalRegister
from qiskit import Aer, execute
import numpy as np

def grover_algorithm(n_qubits, target_item):
    # Create quantum circuit
    qreg = QuantumRegister(n_qubits)
    creg = ClassicalRegister(n_qubits)
    qc = QuantumCircuit(qreg, creg)
    
    # Initialize superposition
    for qubit in range(n_qubits):
        qc.h(qubit)
    
    # Number of iterations
    iterations = int(np.pi/4 * np.sqrt(2**n_qubits))
    
    for _ in range(iterations):
        # Oracle
        oracle_circuit(qc, target_item, n_qubits)
        
        # Diffusion operator
        diffusion_operator(qc, n_qubits)
    
    # Measurement
    qc.measure(qreg, creg)
    
    return qc

def oracle_circuit(qc, target, n_qubits):
    # Mark target state
    # Implementation depends on specific target
    pass

def diffusion_operator(qc, n_qubits):
    # Hadamard all qubits
    for qubit in range(n_qubits):
        qc.h(qubit)
    
    # Flip around |00...0>
    for qubit in range(n_qubits):
        qc.x(qubit)
    
    # Multi-controlled Z
    qc.h(n_qubits-1)
    qc.mcx(list(range(n_qubits-1)), n_qubits-1)
    qc.h(n_qubits-1)
    
    # Flip back
    for qubit in range(n_qubits):
        qc.x(qubit)
    
    # Hadamard all qubits
    for qubit in range(n_qubits):
        qc.h(qubit)