// Bernstein–Vazirani for the secret 0b1011, its oracle a subroutine over a
// qubit register that reads the secret's bits on reading: every shot reads the
// secret, r[i] its bit i.
OPENQASM 3.1;
include "stdgates.inc";
const uint[4] secret = 0b1011;
def oracle(qubit[4] x, qubit y) {
  for uint i in [0:3] {
    if (((secret >> i) & 1) == 1) {
      cx x[i], y;
    }
  }
}
qubit[4] x;
qubit y;
bit[4] r;
x y;
h y;
h x;
oracle(x, y);
h x;
r = measure x;