标签：mos min UI ref input 分享 can lists connect
We can choose between two standard ways to represent a graph
as a collection of adjacency lists or as an adjacency matrix. Either way applies
to both directed and undirected graphs. Because the adjacency-list representation
provides a compact way to represent sparse graphs—those for which
less than V ^2—it is usually the method of choice. Most of the graph algorithms
presented in this book assume that an input graph is represented in adjacencylist
form. We may prefer an adjacency-matrix representation, however, when the
graph is dense—E is close to V^2—or when we need to be able to tell quickly
if there is an edge connecting two given vertices.
A potential disadvantage of the adjacency-list representation is that it provides
no quicker way to determine whether a given edge .u; / is present in the graph
than to search for in the adjacency list AdjOEu. An adjacency-matrix representation
of the graph remedies this disadvantage, but at the cost of using asymptotically
more memory.
the adjacency matrix A of an undirected graph is its own transpose: A = AT.
In some applications, it pays to store only the entries on and above the diagonal of
the adjacency matrix, thereby cutting the memory needed to store the graph almost
in half.
标签：mos min UI ref input 分享 can lists connect
原文地址：http://www.cnblogs.com/wujunde/p/7134307.html
