- Remove nodes v with deg(v) = 1 from N.
Decide optimally if $\delta(v)$ is in the cover and adds it accordingly;
remove node v and $\delta(v)$, add b(v) to b(w) where w is the neighbour of v.
Assumes l = 0.
Args: N: network problem
Returns: Partial cover
- Removes all nodes v with b(v)=0 and deg(v)=1 from N.