© 1976 by British Computer Society
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Algorithms for finding in the lump both bounds of the chromatic number of a graph*


1 Hankyu Corporation, Japan, 2 Department of Electronics, Himeji Institute of Technology, Japan, 3 Institute of Atomic Energy, Kyoto University, Kyoto, Japan
Many problems of scheduling or timetabling are reduced to finding the chromatic number of a graph, i.e. the minimum number of colours assigned to vertices so that no two adjacent vertices have the same colour. In this paper algorithms for finding in the lump a lower bound and an upper bound of the chromatic number are given. The results obtained for several graphs by the computer are indicated and compared with other methods.
Received September 1974.
* This work was performed at the Insitute of Atomic Energy, Kyoto University, Uji Kyoto-Fu 611, Japan.
¶ Department of Electronics, Himeji Institute of Technology, Japan.
Hankyu Corporation, Japan.
Institute of Atomic Energy, Kyoto University, Japan.