Black-and-White Threshold Graphs
نویسندگان
چکیده
Let k be a natural number. We introduce k-threshold graphs. We show that there exists anO(n) algorithm for the recognition of k-threshold graphs for each natural number k. k-Threshold graphs are characterized by a finite collection of forbidden induced subgraphs. For the case k = 2 we characterize the partitioned 2threshold graphs by forbidden induced subgraphs. We introduce restricted, and special 2-threshold graphs. We characterize both classes by forbidden induced subgraphs. The restricted 2-threshold graphs coincide with the switching class of threshold graphs. This provides a decomposition theorem for the switching class of threshold graphs.
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