摘要
The problem of complementary cycles in tournaments and bipartite tournaments was completely solved. However, the problem of complementary cycles in semicomplete n-partite digraphs with n 〉 3 is still open. Based on the definition of componentwise complementary cycles, we get the following result. Let D be a 2-strong n-partite (n 〉 6) tournament that is not a tournament. Let C be a 3-cycle of D and D / V(C) be nonstrong. For the unique acyclic sequence D1, D2,..., Da of D / V(C), where a 〉 2, let Dc = {Di|Di contains cycles, i = 1,2,...,a}, Dc = {D1,D2,...,Da} / De. If Dc≠ 0, then D contains a pair of componentwise complementary cycles.
The problem of complementary cycles in tournaments and bipartite tournaments was completely solved. However, the problem of complementary cycles in semicomplete n-partite digraphs with n 〉 3 is still open. Based on the definition of componentwise complementary cycles, we get the following result. Let D be a 2-strong n-partite (n 〉 6) tournament that is not a tournament. Let C be a 3-cycle of D and D / V(C) be nonstrong. For the unique acyclic sequence D1, D2,..., Da of D / V(C), where a 〉 2, let Dc = {Di|Di contains cycles, i = 1,2,...,a}, Dc = {D1,D2,...,Da} / De. If Dc≠ 0, then D contains a pair of componentwise complementary cycles.
基金
Supported by the National Natural Science Foundation of China (No. 10801114)
the Nature Science Foundation of Shandong Province, China (No. ZR2011AL019
No. ZR2011AM005)