Steiner Minimal Trees on Zig-Zag Lines
D. Z. Du, F. K. Hwang, J. F. Weng · Transactions of the American Mathematical Society · 1983
A Steiner minimal tree for a given set $P$ of points in the Euclidean plane is a shortest network interconnecting $P$ whose vertex set may include some additional points. The construction of Steiner minimal trees has been proved to be an $NP$-complete problem for general $P$. However, the $NP$-completeness does not exclude the possibility that Steiner trees for sets of points with special structures can be efficiently determined. In this paper we determine the Steiner mimmal trees for zig-zag lines with certain regularity properties. We also give an explicit formula for the length of such a tree.