An Overview of Algorithms for Network Survivability

Algorithm 6

Eswaran-Tarjan-2-link-augmentation (𝐺).

(1) Find the 2-link-connected components of 𝐺

(2) Condense 𝐺 into a tree 𝑇 for which each node represents one of the 2-link-

    connected components of 𝐺

(3) Number the nodes in 𝑇 in preorder, starting from an arbitrary non-leaf node

    𝑠 /*PreOrder (𝑇,𝑠,0)*/

(4) For 𝑖=1,…,⌈𝑟/2⌉ choose links (𝑢(𝑖),𝑢(𝑖+⌊𝑟/2⌋)), where 𝑢(𝑖),…,𝑢(𝑟) are the

    𝑟 leaves of 𝑇 ordered in increasing node number

(5) Map the ends of each chosen link to an arbitrary node in the corresponding

    2-link-connected component