Problem 22-4

1. Transpose G into G’
2. DFS in G’ from minimum number.

If u is reachable from v in G’, then v is reachable from u in G. Since we start the DFS with minimum number, we can find the minimum node which is reachable from u.

Problem 22-3

It is a classical problem in graph theory. It is called Fleury’s algorithm. See reference.

Problem 22-2

This is the classical problem in graph theory. See reference.

Problem 22-1