Контуры малой длины в эйлеровых ориентациях графов

In this paper we investigate estimates for number of 3-, 4- and 5-circuits in eulerian tournaments and 4-circuits in eulerian orientations of complete bipartite graphs and hypercubes. By using obtained relations, we prove uniqueness (up to isomorphism) of orientations, which reach maximum number of 4-circuits in all graph families mentioned above.