这是微软量子卡塔练习中的一个问题。
// Input: Two qubits (stored in an array) which are guaranteed to be
// either in superposition of states |00⟩ and |11⟩
// or in superposition of states |01⟩ and |10⟩.
// Output: 0 if qubits were in the first superposition,
// 1 if they were in the second supe