Цитата:
A linear-time isomorphism algorithm for trees, found by Jack Edmonds, appears in the book by A. V. Aho, J. E. Hopcroft and J. D. Ullman [The design and analysis of computer algorithms, Addison-Wesley, Reading, Mass., 1974; MR 54 #1706] and has been used to find a coding for trees---a function on trees in which two trees get the same value if and only if they are isomorphic. This result was used by M. Fontet [Automata, languages and programming (Edinburgh, 1976), pp. 411--424, Edinburgh Univ. Press, Edinburgh, 1976] to construct a linear-time algorithm for finding the automorphism partition---that is, the set of orbits of the automorphism group acting on the vertex-set---of a tree.
описание алгоритма Gabriel'ом Valiente
