  We demonstrated the detailed construction of the hybrid quantum-classical
computer. Based on this architecture, the useful concept of amplitude
interception is illustrated. It is then embedded into a combination of
Depth-First Search and Grover's algorithm to generate a novel approach, the
Depth-First Grover Search(DFGS), to handle multi-solution searching problems on
unstructured databases with an unknown number of solutions. Our new algorithm
attains an average complexity of $\mathcal{O}(m\sqrt{N})$ which performs as
efficient as a normal Grover Search, and a $\mathcal{O}(\sqrt{p}N)$ complexity
with a manually determined constant $p$ for the case with all elements are
solutions, where a normal Grover Search will degenerate to
$\mathcal{O}(N\sqrt{N})$. The DFGS algorithm is more robust and stable in
comparison.
