如果G的边集E(G)中有个子集M，满足M中的任何两条边 都不邻接，则M就是图G的一个匹配。包含边数最多的匹配 称为最大匹配，最大匹配所包含的边数称为最大匹配数。当 G是二分图时，问题就比较特殊了，这就是我们要解决 的问题——最大二分匹配。(If there is a subset M in the edge set E (G) of G, if any two edges in M are not adjacent, then M is a match of graph G. The match with the largest number of edges is called the maximum matching, and the number of edges contained in the maximum matching is called the maximum matching number. When G is a two point graph, the problem is very special. This is the problem we want to solve -- the biggest two points matching.)