We present a polynomial-time approximation algorithm for legally coloring as many edges of a given simple graph as possible using two colors. It achieves an approximation ratio of frac(468, 575). This improves on the previous best (trivial) ratio of frac(4, 5). © 2007 Elsevier B.V. All rights reserved.
Chen, Z. Z., Tanahashi, R., & Wang, L. (2008). An improved approximation algorithm for maximum edge 2-coloring in simple graphs. Journal of Discrete Algorithms, 6(2), 205–215. https://doi.org/10.1016/j.jda.2007.08.002