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：我们提出一种旅行商问题的$\frac{4}{3}$近似算法，其中点之间的距离由无权重图中的图论距离诱导。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成本完美匹配。