Quantum Search Algorithm for Set Operation
  The operations of data set, such as intersection, union and complement, are the fundamental calculation in mathematics. It's very significant that designing fast algorithm for set operation. In this paper, the quantum algorithm for intersection is presented. And its running time is sqrt(|A|*|B|*|C|) for set operation C = A intersection B, while classical computation needs O (|A| *|B|) steps of computation in general, where |.| denotes the size of set. The presented algorithm is the combination of Grover's algorithm, classical memory and classical iterative computation, and the combination method decrease the complexity of designing quantum algorithm.The method can be used to design other set operations also. Keywords: Set operation, General Grover iteration, Grover's algorithm 
Chao-Yang Pang, Cong-Bao Ding, and Ben-Qiong Hu