  Two problems in the search of metric characteristics on weighted undirected
graphs with non-negative edge weights are being considered. The first problem:
a weighted undirected graph with non-negative edge weight is given. The radius,
diameter and at least one center and one pair of peripheral vertices of the
graph are to be found. In the second problem we have additionally calculated
the distances matrix. For the problems being considered, we proposed fast
search algorithms which use only small fraction of graph's vertices for the
search of the metric characteristics. The proposed algorithms have been
compared to other popular methods of solving problems considered on various
inputs.
