We describe a $\frac{4}{3}$-approximation algorithm for the traveling salesman problem in which the distances between points are induced by graph-theoretical distances in an unweighted graph. The algorithm is based on finding a minimum cost perfect matching on the odd degree vertices of a carefully computed 2-edge-connected spanning subgraph.

翻译：我们描述了一种针对旅行商问题的 $\frac{4}{3}$ 近似算法，其中点之间的距离由无权图中图论距离诱导产生。该算法基于在精心计算的2-边连通生成子图的奇度顶点上寻找最小代价完美匹配。