Fredkin gate (CSWAP)
QuantumFredkin gate (CSWAP): A three-qubit gate that swaps two target qubits only when a control qubit is one; it is reversible and preserves the number of ones.
Fredkin gate (CSWAP): A three-qubit gate that swaps two target qubits only when a control qubit is one; it is reversible and preserves the number of ones.