@book{330b8c40c05744a8ae983b23130644a7,
title = "Directed paths with few or many colors in colored directed graphs",
abstract = "Given a graph \$D=(V(D),A(D))\$ and a coloring of \$D\$, not necessarily a proper coloring of either the arcs or the vertices of \$D\$, we consider the complexity of finding a path of \$D\$ from a given vertex \$s\$ to another given vertex \$t\$ with as few different colors as possible, and of finding one with as many different colors as possible. We show that the first problem is polynomial-time solvable, and that the second problem is NP-hard.",
keywords = "MSC-90C27, MSC-05C85, MSC-90C35",
author = "X. Li and S. Zhang and H.J. Broersma",
year = "2000",
language = "Undefined",
series = "Memorandum Faculteit TW",
publisher = "University of Twente",
number = "1543",
address = "Netherlands",
}