construct/nppc three coloring

construct/nppc three coloring: a task in MathConstructOptimize-Envs-harbor (Harbor dataset). Graph with 60 vertices labelled 0..59 and edge list 0, 2 , 0, 34 , 0, 39 , 0, 45 , 1, 13 , 1, 32 , 2, 3 , 2, 13 , 2, 15 , 2, 24 , 2, 41 , 3, 10 , 3, 18 , 3, 37 , 3, 42 , 3, 44 , 3, 47 , 3, 53 , 4, 8 , 4…