input.groovy

g = TinkerGraph.open().traversal()
g.addV().property('name','united states').as('united states').
addV().property('name', 'california').as('california').
addV().property('name', 'los angeles').as('los angeles').
addV().property('name', 'san francisco').property('marked', 'true').as('san francisco').
addE('contains').from('united states').to('california').
addE('contains').from('california').to('los angeles').
addE('contains').from('california').to('san francisco').

addV().property('name', 'texas').as('texas').
addV().property('name', 'dallas').as('dallas').
addV().property('name', 'houston').as('houston').
addE('contains').from('united states').to('texas').
addE('contains').from('texas').to('dallas').
addE('contains').from('texas').to('houston').

addV().property('name', 'arizona').as('arizona').
addV().property('name', 'pima').as('pima').
addV().property('name', 'maricopa').as('maricopa').
addV().property('name', 'tucson').property('marked', 'true').as('tucson').
addV().property('name', 'phoenix').as('phoenix').
addE('contains').from('united states').to('arizona').
addE('contains').from('arizona').to('pima').
addE('contains').from('arizona').to('maricopa').
addE('contains').from('pima').to('tucson').
addE('contains').from('maricopa').to('phoenix')

solution1 = {
  g.V().has('name', 'united states').
    until(select('result').or().not(outE('contains'))).
      repeat(sack(assign).
             map(out('contains').
                 group().
                   by(coalesce(values('marked'), constant('false')))).
             choose(select('true'),
                      coalesce(select('false'), sack()).project('result'),
                      select('false').unfold())).
    coalesce(select('result').unfold(),
             sack()).dedup().
    values('name')
}

solution2 = {
  g.V().has('name', 'united states').
    until(select('result').or().not(outE('contains'))).
      repeat(sack(assign).
             map(out('contains').
                 group().
                   by(coalesce(values('marked'), constant('false')))).
             choose(select('true'),
                      union(select('false').unfold(), sack().project('result')),
                      select('false').unfold())).
    coalesce(select('result').unfold(),
             sack()).dedup().
    values('name')
}

solution1()
solution2()

g.V().has('name', 'tucson').properties('marked').drop()
g.V().has('name', 'pima').property('marked', 'true').iterate()


solution1()
solution2()

output.txt

gremlin> g = TinkerGraph.open().traversal()
==>graphtraversalsource[tinkergraph[vertices:0 edges:0], standard]
gremlin> g.addV().property('name','united states').as('united states').
......1> addV().property('name', 'california').as('california').
......2> addV().property('name', 'los angeles').as('los angeles').
......3> addV().property('name', 'san francisco').property('marked', 'true').as('san francisco').
......4> addE('contains').from('united states').to('california').
......5> addE('contains').from('california').to('los angeles').
......6> addE('contains').from('california').to('san francisco').
......7> 
......7> addV().property('name', 'texas').as('texas').
......8> addV().property('name', 'dallas').as('dallas').
......9> addV().property('name', 'houston').as('houston').
.....10> addE('contains').from('united states').to('texas').
.....11> addE('contains').from('texas').to('dallas').
.....12> addE('contains').from('texas').to('houston').
.....13> 
.....13> addV().property('name', 'arizona').as('arizona').
.....14> addV().property('name', 'pima').as('pima').
.....15> addV().property('name', 'maricopa').as('maricopa').
.....16> addV().property('name', 'tucson').property('marked', 'true').as('tucson').
gremlin> g = TinkerGraph.open().traversal()
==>graphtraversalsource[tinkergraph[vertices:0 edges:0], standard]
gremlin> g.addV().property('name','united states').as('united states').
......1> addV().property('name', 'california').as('california').
......2> addV().property('name', 'los angeles').as('los angeles').
......3> addV().property('name', 'san francisco').property('marked', 'true').as('san francisco').
......4> addE('contains').from('united states').to('california').
......5> addE('contains').from('california').to('los angeles').
......6> addE('contains').from('california').to('san francisco').
......7> 
......7> addV().property('name', 'texas').as('texas').
......8> addV().property('name', 'dallas').as('dallas').
......9> addV().property('name', 'houston').as('houston').
.....10> addE('contains').from('united states').to('texas').
.....11> addE('contains').from('texas').to('dallas').
.....12> addE('contains').from('texas').to('houston').
.....13> 
.....13> addV().property('name', 'arizona').as('arizona').
.....14> addV().property('name', 'pima').as('pima').
.....15> addV().property('name', 'maricopa').as('maricopa').
.....16> addV().property('name', 'tucson').property('marked', 'true').as('tucson').
.....17> addV().property('name', 'phoenix').as('phoenix').
.....18> addE('contains').from('united states').to('arizona').
.....19> addE('contains').from('arizona').to('pima').
.....20> addE('contains').from('arizona').to('maricopa').
.....21> addE('contains').from('pima').to('tucson').
.....22> addE('contains').from('maricopa').to('phoenix')
==>e[36][25-contains->30]
gremlin> 
gremlin> solution1 = {
......1>   g.V().has('name', 'united states').
......2>     until(select('result').or().not(outE('contains'))).
......3>       repeat(sack(assign).
......4>              map(out('contains').
......5>                  group().
......6>                    by(coalesce(values('marked'), constant('false')))).
......7>              choose(select('true'),
......8>                       coalesce(select('false'), sack()).project('result'),
......9>                       select('false').unfold())).
.....10>     coalesce(select('result').unfold(),
.....11>              sack()).dedup().
.....12>     values('name')
.....13> }
==>groovysh_evaluate$_run_closure1@3f63a513
gremlin> 
gremlin> solution2 = {
......1>   g.V().has('name', 'united states').
......2>     until(select('result').or().not(outE('contains'))).
......3>       repeat(sack(assign).
......4>              map(out('contains').
......5>                  group().
......6>                    by(coalesce(values('marked'), constant('false')))).
......7>              choose(select('true'),
......8>                       union(select('false').unfold(), sack().project('result')),
......9>                       select('false').unfold())).
.....10>     coalesce(select('result').unfold(),
.....11>              sack()).dedup().
.....12>     values('name')
.....13> }
==>groovysh_evaluate$_run_closure1@53f0d09c
gremlin> 
gremlin> solution1()
==>texas
==>los angeles
==>pima
==>maricopa
gremlin> solution2()
==>texas
==>california
==>pima
==>maricopa
gremlin> 
gremlin> g.V().has('name', 'tucson').properties('marked').drop()
gremlin> g.V().has('name', 'pima').property('marked', 'true').iterate()
gremlin> 
gremlin> 
gremlin> solution1()
==>maricopa
==>texas
==>los angeles
gremlin> solution2()
==>arizona
==>texas
==>california
==>maricopa
gremlin>