Add optional start vertex to maximum_adjacency_visit

[jonas-schulze]

Only after I had already done the modifications I noticed that I could also perform the search on a permuted graph:

d = # some graph
s = 3
p = vcat(s, 1:s-1, s+1:nv(d))
d2 = d[p]
maximum_adjacency_visit(d2)
# instead of maximum_adjacency_visit(d, s)

How much more expensive would that be in practice?

Depending on how the priority queue works, the results might differ slightly. Is this change desirable anyway? If not, feel free to close. 🙂

[codecov]

Codecov Report

Merging #1543 (c355b7b) into master (ebe33dc) will decrease coverage by 0.00%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #1543      +/-   ##
==========================================
- Coverage   99.37%   99.37%   -0.01%     
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  Files         108      108              
  Lines        5157     5156       -1     
==========================================
- Hits         5125     5124       -1     
  Misses         32       32