The purpose of this note is to present a polynomial-time algorithm which, given an arbitrary graph G as its input, finds either a proper 3-coloring of G or an odd-K4 that is a subgraph of G in time O(mn), where m and n stand for the number of edges and the number of vertices of G, respectively. © 1998 Published by Elsevier Science B.V. All rights reserved.
Zang, W. (1998). Coloring graphs with no odd-K4. Discrete Mathematics, 184(1–3), 205–212. https://doi.org/10.1016/S0012-365X(97)00090-3