说明：  k-means 算法接受输入量 k ；然后将n个数据对象划分为 k个聚类以便使得所获得的聚类满足：同一聚类中的对象相似度较
(The k-means algorithm accepts the input quantity k, and then divides n data objects into k clusters so as to satisfy the obtained clustering: the similarity of objects in the same cluster is higher than that in the same clustering.)