Distances in Orientations of Graphs.
Abstract
The authors prove that there is a function h(k) such that every undirected graph G admits an orientation H with the following property: if an edge uv belongs to a cycle of length k in G then uv or vu belongs to a directed cycle of length at most h(k) in H. Next, it is shown that every undirected bridgeless graph of radius r admits an orientation of radius at most (r sup 2)+ r, and this bound is best possible. The same problem is considered with radius replaced by diameter. Finally, it is shown that the problem of deciding whether an undirected graph admits an orientation of diameter (resp. radius) two belongs to a class of problems called NP-hard.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1975
- Accession Number
- ADA018426
Entities
People
- G. Thomassen
- V. Chvatal
Organizations
- Stanford University