反对半后卫
Opposing Half Guards
摘要：
我们研究了反对半后卫的画廊问题：后卫可以看到他们的左边或他们的右边。我们提出了画廊定理，表明在2-guardable多边形的半后卫的位置不限于扩展，表明该问题是NP-困难的单调多边形，并提出近似算法的螺旋和楼梯多边形。
英文摘要：
We study the art gallery problem for opposing half guards: guards that can either see to their left or to their right only. We present art gallery theorems, show that the location of half guards in 2-guardable polygons is not restricted to extensions, show that the problem is NP-hard in monotone polygons, and present approximation algorithms for spiral and staircase polygons.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
