关于排列的型

On The Type Of Permutations

本文确定了任一三元非负整数组(s,i,d)恰为某个n排列的型的充分必要条件,并通过型在全体n排列的集合上定义了一个等价关系,明确给出了计算等价类的数目和每个等价类中所包含的排列个数的公式。

In this paper we determine the necessary and sufficient condition for any triple of non-negative integers (s, i, d) to be the type of some n-permutation. An equival- ence relation is defined on the set of all n-permutations according to their types. The formulas for calculating the numbers of equivalence classes and the permutations contained in each class are presented.