非负整数序列是可2—重图的充分必要条件

The Necessary and Sufficient Condition in Which a Sequence of Nonnegative Integer Is Potentially 2-multigraph

对于给定的非负整数序列π =(d1,d2 ,… ,dn) ,给出π是

For sequence of nonnegative integer π=(d 1,d 2,…,d n),the necessary and sufficient condition and method of calculation in which π is degree sequence of 2-multigraph,which is given.