A rooted tree is called a single-branch tree if there is exactly one n
onleaf vertex on each level except the bottom level of the tree. We pr
esent an O(n) time algorithm for finding biconnected components in a g
raph G, assuming that a single-branch breadth-first search (SBS) tree
of any connected induced subgraph of G can be found in O(n) time. We s
how that such SBS trees can be found for the interval graphs and the p
ermutation graphs in O(n) time. Hence, the biconnected components in t
hese graphs can be obtained in O(n) time, while finding biconnected co
mponents in a general graph of n vertices and m edges takes O(m + n) t
ime.