# Game saturation of intersecting families

Open Mathematics (2014)

• Volume: 12, Issue: 9, page 1382-1389
• ISSN: 2391-5455

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## Abstract

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We consider the following combinatorial game: two players, Fast and Slow, claim k-element subsets of [n] = 1, 2, …, n alternately, one at each turn, so that both players are allowed to pick sets that intersect all previously claimed subsets. The game ends when there does not exist any unclaimed k-subset that meets all already claimed sets. The score of the game is the number of sets claimed by the two players, the aim of Fast is to keep the score as low as possible, while the aim of Slow is to postpone the game’s end as long as possible. The game saturation numbers, gsatF(IIn,k) and gsatS(IIn,k), are the score of the game when both players play according to an optimal strategy in the cases when the game starts with Fast’s or Slow’s move, respectively. We prove that ${\Omega }_{k}\left({n}^{k/3-5}\right)⩽gsa{t}_{F}\left({𝕀}_{n,k}\right),gsa{t}_{S}\left({𝕀}_{n,k}\right)⩽{O}_{k}\left({n}^{k-\sqrt{k/2}}\right)$.

## How to cite

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Balázs Patkós, and Máté Vizer. "Game saturation of intersecting families." Open Mathematics 12.9 (2014): 1382-1389. <http://eudml.org/doc/269668>.

@article{BalázsPatkós2014,
abstract = {We consider the following combinatorial game: two players, Fast and Slow, claim k-element subsets of [n] = 1, 2, …, n alternately, one at each turn, so that both players are allowed to pick sets that intersect all previously claimed subsets. The game ends when there does not exist any unclaimed k-subset that meets all already claimed sets. The score of the game is the number of sets claimed by the two players, the aim of Fast is to keep the score as low as possible, while the aim of Slow is to postpone the game’s end as long as possible. The game saturation numbers, gsatF(IIn,k) and gsatS(IIn,k), are the score of the game when both players play according to an optimal strategy in the cases when the game starts with Fast’s or Slow’s move, respectively. We prove that $\Omega _k (n^\{k/3 - 5\} ) \leqslant gsat_F (\mathbb \{I\}_\{n,k\} ),gsat_S (\mathbb \{I\}_\{n,k\} ) \leqslant O_k (n^\{k - \sqrt\{k/2\} \} )$.},
author = {Balázs Patkós, Máté Vizer},
journal = {Open Mathematics},
keywords = {Intersecting families of sets; Saturated families; Positional games; intersecting families of sets; saturated families; positional games},
language = {eng},
number = {9},
pages = {1382-1389},
title = {Game saturation of intersecting families},
url = {http://eudml.org/doc/269668},
volume = {12},
year = {2014},
}

TY - JOUR
AU - Balázs Patkós
AU - Máté Vizer
TI - Game saturation of intersecting families
JO - Open Mathematics
PY - 2014
VL - 12
IS - 9
SP - 1382
EP - 1389
AB - We consider the following combinatorial game: two players, Fast and Slow, claim k-element subsets of [n] = 1, 2, …, n alternately, one at each turn, so that both players are allowed to pick sets that intersect all previously claimed subsets. The game ends when there does not exist any unclaimed k-subset that meets all already claimed sets. The score of the game is the number of sets claimed by the two players, the aim of Fast is to keep the score as low as possible, while the aim of Slow is to postpone the game’s end as long as possible. The game saturation numbers, gsatF(IIn,k) and gsatS(IIn,k), are the score of the game when both players play according to an optimal strategy in the cases when the game starts with Fast’s or Slow’s move, respectively. We prove that $\Omega _k (n^{k/3 - 5} ) \leqslant gsat_F (\mathbb {I}_{n,k} ),gsat_S (\mathbb {I}_{n,k} ) \leqslant O_k (n^{k - \sqrt{k/2} } )$.
LA - eng
KW - Intersecting families of sets; Saturated families; Positional games; intersecting families of sets; saturated families; positional games
UR - http://eudml.org/doc/269668
ER -

## References

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