Greedy and lazy representations in negative base systems
Kybernetika, Tome 49 (2013) no. 2, pp. 258-279
Cet article a éte moissonné depuis la source Czech Digital Mathematics Library
We consider positional numeration systems with negative real base $-\beta$, where $\beta>1$, and study the extremal representations in these systems, called here the greedy and lazy representations. We give algorithms for determination of minimal and maximal $(-\beta)$-representation with respect to the alternate order. We also show that both extremal representations can be obtained as representations in the positive base $\beta^2$ with a non-integer alphabet. This enables us to characterize digit sequences admissible as greedy and lazy $(-\beta)$-representation. Such a characterization allows us to study the set of uniquely representable numbers. In the case that $\beta$ is the golden ratio and the Tribonacci constant, we give the characterization of digit sequences admissible as greedy and lazy $(-\beta)$-representation using a set of forbidden strings.
We consider positional numeration systems with negative real base $-\beta$, where $\beta>1$, and study the extremal representations in these systems, called here the greedy and lazy representations. We give algorithms for determination of minimal and maximal $(-\beta)$-representation with respect to the alternate order. We also show that both extremal representations can be obtained as representations in the positive base $\beta^2$ with a non-integer alphabet. This enables us to characterize digit sequences admissible as greedy and lazy $(-\beta)$-representation. Such a characterization allows us to study the set of uniquely representable numbers. In the case that $\beta$ is the golden ratio and the Tribonacci constant, we give the characterization of digit sequences admissible as greedy and lazy $(-\beta)$-representation using a set of forbidden strings.
Classification :
11A63, 11A67, 37B10
Keywords: numeration systems; lazy representation; greedy representation; negative base; unique representation
Keywords: numeration systems; lazy representation; greedy representation; negative base; unique representation
@article{KYB_2013_49_2_a4,
author = {Hejda, Tom\'a\v{s} and Mas\'akov\'a, Zuzana and Pelantov\'a, Edita},
title = {Greedy and lazy representations in negative base systems},
journal = {Kybernetika},
pages = {258--279},
year = {2013},
volume = {49},
number = {2},
mrnumber = {3085396},
zbl = {1275.11020},
language = {en},
url = {http://geodesic.mathdoc.fr/item/KYB_2013_49_2_a4/}
}
Hejda, Tomáš; Masáková, Zuzana; Pelantová, Edita. Greedy and lazy representations in negative base systems. Kybernetika, Tome 49 (2013) no. 2, pp. 258-279. http://geodesic.mathdoc.fr/item/KYB_2013_49_2_a4/