How do I use igraph calculation and output weakly connected branch of a directed graph, using decompose function output, but for such a picture:


(1, 2), (2, 3), (3, 4), (4, 1), (5, 6), (7, 8), (8, 9)

Output the result is:

(1, 2), (2, 3), (3, 4), (4, 1), (1, 2), (1, 2), (2, 3)