給定含有n 個(gè)元素的多重集合S = {a1, a2,., an } ，1 ≤ ai ≤ n ，1 ≤ i ≤ n ，每個(gè)元素在S 中出現(xiàn)的次數(shù)稱為該元素的重?cái)?shù)。多重集S 中重?cái)?shù)大于n/2 的元素稱為主元素。例如，S={2，2，4，2，1，2，5，2，2，8}。多重集S 的主元素是2，其重?cái)?shù)為6。
This Handbook, published under the auspices of the Senior NATO
Logisticians’ Conference (SNLC), i s i ntended as a simple guide to logistics i n
NATO. It does not attempt to examine current i ssues or provide answers to the
problems that logisticians will face, but i t rather aims at i ntroducing them to some
of the basic principles, policies, concepts and organisations with which they will
work.
