The minimum firing time of the generalized firing squad synchronization problem for squares
The minimum firing time of the generalized firing squad synchronization problem for squares
复制标题
方格广义行刑队同步问题的最小开火时间
DOI:
10.1016/j.tcs.2014.06.016
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发表时间:
2014
期刊:
影响因子:
--
通讯作者:
Kojiro Kobayashi
中科院分区:
文献类型:
--
作者:
Kojiro Kobayashi
For almost all variations of the firing squad synchronization problem for elementary geometric figures such as lines, rings, squares, rectangles, and cubes, minimal-time solutions are known. However, in 2012 Umeo and Kubo introduced a very simple variation of this type and pointed out that its minimal-time solutions are unknown. In that variation, a problem instance is a square array of n columns and n rows and the position of the general is arbitrary. For this variation they constructed a solution that fires at time 2 n− 2 for any position of the general and wrote that it is not known whether this solution is minimal-time or not. We determine the exact value of the minimum firing time of this variation. For some problem instances this value is smaller than 2 n− 2 and hence the 2 n− 2 time solution is not minimal-time. Our result does not solve the problem of existence or non-existence of minimal-time solutions of the variation. However the result gives one necessary condition for solutions to be minimal-time.