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本词条由Ryan初步翻译

本词条由Ryan初步翻译

{{Redirect|Geodesic distance|distances on the surface of a sphere|Great-circle distance|distances on the surface of the Earth|Geodesics on an ellipsoid|geodesics in differential geometry|Geodesic}}

{{Redirect|Geodesic distance|distances on the surface of a sphere|Great-circle distance|distances on the surface of the Earth|Geodesics on an ellipsoid|geodesics in differential geometry|Geodesic}}

In the case of a directed graph the distance <math>d(u,v)</math> between two vertices <math>u</math> and <math>v</math> is defined as the length of a shortest directed path from <math>u</math> to <math>v</math> consisting of arcs, provided at least one such path exists. Notice that, in contrast with the case of undirected graphs, <math>d(u,v)</math> does not necessarily coincide with <math>d(v,u)</math>, and it might be the case that one is defined while the other is not.

In the case of a directed graph the distance <math>d(u,v)</math> between two vertices <math>u</math> and <math>v</math> is defined as the length of a shortest directed path from <math>u</math> to <math>v</math> consisting of arcs, provided at least one such path exists. Notice that, in contrast with the case of undirected graphs, <math>d(u,v)</math> does not necessarily coincide with <math>d(v,u)</math>, and it might be the case that one is defined while the other is not.

在有向图中，两个顶点之间 <math>u</math><math>v</math>的距离<math>d(u,v)</math>被定义为从<math>u</math> 到 <math>v</math>之间由弧组成的最短有向路径的长度，但前提是至少存在一条这样的路径。请注意，与无向图不同， <math>d(u,v)</math> 不一定与<math>d(v,u)</math>一致，而且可能一个是符合定义的，而另一个不是。

在有向图中，两个顶点之间 <math>u</math><math>v</math>的距离<math>d(u,v)</math>被定义为从<math>u</math> 到 <math>v</math>之间由弧组成的最短有向路径的长度，但前提是至少存在一条这样的路径。请注意，与无向图不同， <math>d(u,v)</math> 不一定与<math>d(v,u)</math>一致，而且可能一个是符合定义的，而另一个不符合。