更改

A graph data structure may also associate to each edge some edge value, such as a symbolic label or a numeric attribute (cost, capacity, length, etc.).

A graph data structure may also associate to each edge some edge value, such as a symbolic label or a numeric attribute (cost, capacity, length, etc.).

图形数据结构还可以为每个边关联一些边值，如符号标签或数字属性(成本、容量、长度等)。).

图形数据结构还可以为每个边关联一些边值，如符号标签或数字属性(成本、容量、长度等)。

The basic operations provided by a graph data structure G usually include:

The basic operations provided by a graph data structure G usually include:

图形数据结构 G 提供的基本操作通常包括:

图形''G'' 的数据结构提供的基本操作通常包括:

   --[[用户:趣木木|趣木木]]（[[用户讨论:趣木木|讨论]]）变量斜体

   --[[用户:趣木木|趣木木]]（[[用户讨论:趣木木|讨论]]）变量斜体

* <code>adjacent</code>(''''G'''', ''''x'''', ''''y''''): tests whether there is an edge from the vertex ''x'' to the vertex ''y'';

* <code>adjacent</code>(''''G'''', ''''x'''', ''''y''''): tests whether there is an edge from the vertex ''''x'''' to the vertex ''''y'''';

* <code>neighbors</code>(''G'', ''x''): lists all vertices ''y'' such that there is an edge from the vertex ''x'' to the vertex ''y'';

* <code>neighbors</code>(''''G'''', ''''x''''): lists all vertices ''''y'''' such that there is an edge from the vertex ''''x'''' to the vertex ''''y'''';

* <code>add_vertex</code>(''G'', ''x''): adds the vertex ''x'', if it is not there;

* <code>add_vertex</code>(''''G'''', ''''x''''): adds the vertex ''''x'''', if it is not there;

* <code>remove_vertex</code>(''G'', ''x''): removes the vertex ''x'', if it is there;

* <code>remove_vertex</code>(''G'', ''x''): removes the vertex ''x'', if it is there;