Simplify by removing a small optimization
Simplify by removing a small optimization

In my benchmarks, the 7% improvement to array access yields 0.8s
savings after 1e8 writes.  If we extrapolate, add_blossom can be
expected to perform 2v writes and 1v reads where v is the number
of vertexes in the blossom.  To represent our design goal of graphs
in the hectovertex to kilovertex range, let's assume 3e3 accesses,
yielding an expected 2.4e-5 seconds, or 24 microseconds per
add_blossom.

So, if my math is correct, I don't think this savings is worth
the code complexity.  Then again, I have no idea how many times
add_blossom runs per stage.

jaredbeck/graph_matching,jaredbeck/graph_matching,jaredbeck/graph_matching