Input: graph , sink  Output: subproblem set  (1) ;  (2) sort nodes in ascending order by initial energy, and let be the sorted list;  (3) while do  (4);  (5)for do  (6);  (7)reverse the directions of edges in and perform a breadthfirst search from the sink  (8)if all vertices are visited then  (9)construct subproblem with as the network;  (10)include to ;  (11) return ; 
