The Toffoli Gate is a three-qubit Quantum Gate that flips the right Qubit if the left and middle qubits are $1$ : $$\begin{aligned} \text{Toffoli}\ket{000} &= \ket{000}, \ \text{Toffoli}\ket{001} &= \ket{001}, \ \text{Toffoli}\ket{010} &= \ket{010}, \ \text{Toffoli}\ket{011} &= \ket{011}, \ \text{Toffoli}\ket{100} &= \ket{100}, \ \text{Toffoli}\ket{101} &= \ket{101}, \ \text{Toffoli}\ket{110} &= \ket{111}, \ \text{Toffoli}\ket{111} &= \ket{110}. \end{aligned}$$
As we know that the Toffoli gate is universal for classical computing, and since it is a Quantum Gate, quantum computers can efficiently do everything a classical computer can efficiently do.
