A k-cycle system of order v with index A, denoted by CS(v, k, λ), is a collection A of k-cycles (blocks) of Kv such that each edge in Kv appears in exactly λ blocks of A. A large set of CS(v, k, λ)s is a part...A k-cycle system of order v with index A, denoted by CS(v, k, λ), is a collection A of k-cycles (blocks) of Kv such that each edge in Kv appears in exactly λ blocks of A. A large set of CS(v, k, λ)s is a partition of the set of all k-cycles of Kv into CS(v, k, λ)s, and is denoted by LCS(v, k, λ). A (v - 1)-cycle in K, is called almost Hamilton. The completion of the existence problem for LCS(v, v- 1,λ) depends only on one case: all v ≥ 4 for λ=2. In this paper, it is shown that there exists an LCS(v,v - 1,2) for all v ≡ 2 (mod 4), v ≥ 6.展开更多
基金Supported in part by the National Natural Science Foundation of China(No.10901051,11201143)the Fundamental Research Funds for the Central Universities(No.2016MS66)the Co-construction Project of Bejing Municipal Commission of Education
文摘A k-cycle system of order v with index A, denoted by CS(v, k, λ), is a collection A of k-cycles (blocks) of Kv such that each edge in Kv appears in exactly λ blocks of A. A large set of CS(v, k, λ)s is a partition of the set of all k-cycles of Kv into CS(v, k, λ)s, and is denoted by LCS(v, k, λ). A (v - 1)-cycle in K, is called almost Hamilton. The completion of the existence problem for LCS(v, v- 1,λ) depends only on one case: all v ≥ 4 for λ=2. In this paper, it is shown that there exists an LCS(v,v - 1,2) for all v ≡ 2 (mod 4), v ≥ 6.