摘要： We prove that the existence of a directed Hamiltonian cycle in a mediate graph is an NP-complete problem.
孙惠泉. RECOGNIZING A MEDIATE GRAPH TO BE HAMILTONIAN[J]. 数学物理学报(英文版), 1988, 8(1): 25-27.
Sun Huiquan. RECOGNIZING A MEDIATE GRAPH TO BE HAMILTONIAN[J]. Acta mathematica scientia,Series B, 1988, 8(1): 25-27.