We present a $2$-approximation algorithm for the Flexible Graph Connectivity problem [AHM20] via a reduction to the minimum cost $r$-out $2$-arborescence problem.

翻译：我们为灵活图形互联互通问题提出一个2美元接近的算法[AHM20],即降低最低成本2美元/美元/美元/美元/美元/美元。