B3: SWAP Qubits

Problem Statement

Implement the operation of swapping two qubit states on a quantum circuit $\mathrm{qc}$ with $2$ qubits.

More precisely, implement the operation defined as

where $a_i$ represents arbitrary probability amplitudes.

Constraints

• You cannnot use Qiskit's SwapGate in this problem.
• Global phase is ignored in judge.
• The submitted code must follow the specified format:

from qiskit import QuantumCircuit
 
 
def solve() -> QuantumCircuit:
    qc = QuantumCircuit(2)
    # Write your code here:
 
    return qc