office building optimization

1. find the best design process for office building design using GP.
   Genome:  a b a a a b
   gene:        a
   gene-metadata: 12345 -> a -> a b a a a b
   gene-metadata: 12344 -> a -> a b a a a b 
   gene-metadata: 21340 -> b -> b b a a a b

2. object-oriented crossover and mutation