from qiskit import QuantumCircuit
from qiskit.circuit import QuantumRegister, ClassicalRegister
import math


def ghz(n):
    qreg = QuantumRegister(n)
    circ = QuantumCircuit(qreg)
    if n > 0 :
        circ.h(qreg[0])
        for i in range(n-1):
            circ.cx(qreg[i], qreg[i+1])
    return circ


# print(ghz(10))

def ex_or(x, y, circ):
    q = QuantumRegister(1)
    circ.add_register(q)
    circ.cx(x, q[0])
    circ.cx(y, q[0])
    return (circ, q[0])

# def ex_or2(circ):
#     q = QuantumRegister(1)
#     circ.add_register(q)
#     circ.cx(, q[0])
#     circ.cx(, q[0])
#     return circ

# qreg_tst = QuantumRegister(2)
# circ_tst = QuantumCircuit(qreg_tst)

# Note that the output will have 3 qubits. 
# print(ex_or(qreg_tst[0],qreg_tst[1], circ_tst)[1])

def g(x, y, z, circ):
    (circ, xy) = ex_or(x, y, circ)
    circ.barrier()
    (circ, yz) = ex_or(y, z, circ)
    circ.barrier()
    (circ, xz) = ex_or(x, z, circ)
    circ.barrier()
    (circ, xyz) = ex_or(x, yz, circ)
    return (circ, x, y,z, xy, yz, xz, xyz)
    

def ccz(x, y, z, circ):
    (circ, x, y,z, xy, yz, xz, xyz) = g(x, y, z, circ)
    circ.barrier()
    g_dg = circ.inverse()
    circ.t(x)
    circ.t(y)
    circ.t(z)
    circ.tdg(xy)
    circ.tdg(yz)
    circ.tdg(xz)
    circ.t(xyz)
    circ = circ.compose(g_dg)
    return circ
    
qreg_tst1 = QuantumRegister(3)
a, b, c = qreg_tst1
circ_tst1 = QuantumCircuit(qreg_tst1)
print(ccz(a,b,c,circ_tst1))