Abstract
This paper deals with a new method of coding unlabeled trees, the resulting code being a string of integers. For a tree onn vertices both the coding and the decoding algorithm work in time 0(n). Givenn the “mean length” of code strings is shorter than with other existing integer string codes. The new coding method is used to derive an algorithm for generating all unlabeled trees of a given size without repetition.
Zusammenfassung
In dieser Arbeit stellen wir ein neues Kodierungsverfahren für freie Bäume vor. Wie bei anderen Methoden werden Tupel aus ganzen Zahlen zur Kodierung verwendet. Sowohl der Kodierungs- als auch der Dekodierungsalgorithmus arbeiten in Zeit 0(n), wennn die Knotenzahl bedeutet. Die “mittlere Kodelänge” des neuen Verfahrens ist kleiner als bei vergleichbaren bekannten Verfahren. Das Verfahren wird zur Herleitung eines Algorithmus verwendet, der die Kodetupel aller freien Bäume gegebenen Umfangs ohne Wiederholung herstellt.
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Tinhofer, G., Schreck, H. Linear time tree codes. Computing 33, 211–225 (1984). https://doi.org/10.1007/BF02242268
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DOI: https://doi.org/10.1007/BF02242268