def mcz_gray(c: Circuit, ctrl: Sequence[int], target: int) -> Circuit:
"""A macro of multi controlled Z gate."""
n_ctrl = len(ctrl)
if n_ctrl == 0:
return c.z[target]
angles = [math.pi / 2**(n_ctrl - 1), -math.pi / 2**(n_ctrl - 1)]
for c0, c1, parity in gen_gray_controls(n_ctrl):
if c0 >= 0:
c.cx[ctrl[c0], ctrl[c1]]
c.cr(angles[parity])[ctrl[c1], target]
return c
def mcr_gray(c: Circuit, theta: float, ctrl: Sequence[int],
target: int) -> Circuit:
"""A macro of multi controlled R gate."""
n_ctrl = len(ctrl)
if n_ctrl == 0:
return c.r(theta)[target]
angles = [theta / 2**(n_ctrl - 1), -theta / 2**(n_ctrl - 1)]
for c0, c1, parity in gen_gray_controls(n_ctrl):
if c0 >= 0:
c.cx[ctrl[c0], ctrl[c1]]
c.cr(angles[parity])[ctrl[c1], target]
return c
