from qiskit import *

qr = QuantumRegister(2)

cr = ClassicalRegister(2)

circuit = QuantumCircuit(qr, cr)

%matplotlib inline

circuit.draw()

circuit.h(qr[0])

circuit.draw(output = 'mpl')

circuit.cx(qr[0], qr[1])

circuit.draw(output='mpl')

circuit.measure(qr, cr)

circuit.draw(output='mpl')

simulator = Aer.get_backend('qasm_simulator')

execute(circuit, backend=simulator)

result = execute(circuit, backend=simulator).result()

from qiskit.tools.visualization import plot_histogram

plot_histogram(result.get_counts(circuit))

# plot_histogram

provider = IBMQ.get_provider('ibm-q')

backend = provider.get_backend('ibmq_16_melbourne') 

job =execute(circuit, backend= backend)

from qiskit.tools.monitor import job_monitor

job_monitor(job)

result = job.result()

plot_histogram(result.get_counts(circuit))

