中文摘要：

为有效解决生物信息学中的基因组断点median问题，针对4个以上环形基因组的一般情形，建立了该问题的图模型。鉴于基因组断点median问题自身的NP-困难性，从问题转化的角度，将其等价地化为图上的旅行商问题（TSP），找出二者之间最优解的关系，进而给出了其P-近似算法，其中p为用于求解TSP问题的近似算法的近似比。对算法的复杂度和近似比进行了分析，基于LINGO软件的算例表明了该算法的可行性和有效性。

英文摘要：

To solve the genome breakpoint median problem in bioinformatics efficiently,a graph model is constructed for the general case where more than 4 circular genomes are involved.In view of the-hardness of the genome breakpoint median problem,it is equivalently transformed into the traveling salesman problem（TSP） in the graph from the angle of problem transformation,then the relationship between their optimal solutions is found and a-approximation algorithm is proposed,where is the approximation ratio of some approximation algorithm for the TSP.After analyzing the complexity and approximation ratio of this algorithm,an instance based on LINGO software demonstrates its feasibility and efficiency.