  In this paper, it is demonstrated that the DNA-based algorithm [Ho et al.
2005] for solving an instance of the clique problem to any a graph G = (V, E)
with n vertices and p edges and its complementary graph G1 = (V, E1) with n
vertices and m = (((n*(n-1))/2)-p) edges can be implemented by Hadamard gates,
NOT gates, CNOT gates, CCNOT gates, Grover's operators, and quantum
measurements on a quantum computer. It is also demonstrated that if Grovers
algorithm is employed to accomplish the readout step in the DNA-based
algorithm, the quantum implementation of the DNA-based algorithm is equivalent
to the oracle work (in the language of Grover's algorithm), that is, the target
state labeling preceding Grover,s searching steps. It is shown that one oracle
work can be completed with O((2 * n) * (n + 1) * (n + 2) / 3) NOT gates, one
CNOT gate and O((4 * m) + (((2 * n) * (n + 1) * (n + 14)) / 6)) CCNOT gates.
This is to say that for the quantum implementation of the DNA-based algorithm
[Ho et al. 2005] a faster labeling of the target state is attained, which also
implies a speedy solution to an instance of the clique problem.
