Speeding Up Exact Algorithms for Maximizing Lifetime of WSNs Using Multiple Cores

Algorithm 3

decomp_directed_cycle.

Input: graph , sink

Output: subproblem set

(1) return   if is a tree;

(2) let be the minimum directed cycle found by the DICIRCUIT algorithm in [13];

(3) if   then //  no cycle

(4)find any vertex with out degree larger than 1, and

insert its out edges into ;

(5) ;

(6) foreach   do

(7);

(8)reverse the direction of edges in , and perform a breadth-first search from the sink;

(9)if  all  vertices are visited  then

(10);

(11)construct subproblem with as the network;

(12) if    then

(13) graph of subproblem ;

(14)return  ;

(15) else

(16)return  ;