Past exam of the year 1 of the computer science course of the University of Oxford / 2023 / Functional programming, design and analysis of algorithms / 6 / a / iii / Solution

The strongly connected components areThe directed cycle $1\to 3\to 5\to 1$ makes its three vertices mutually reachable. Vertex $6$ has no outgoing edge. Vertex $2$ reaches that cycle but has no return path from it, and vertex $4$ reaches the other components but has no incoming path from them. These facts exclude every further merger.