Don't compress the forest before we create a TreeSet

Author: amontoison

src/coloring.jl

@@ -341,10 +341,6 @@ function acyclic_coloring(g::AdjacencyGraph, order::AbstractOrder; postprocessin
         end
     end
 
-    # compress forest
-    for edge in keys(forest.intmap)
-        find_root!(forest, edge)
-    end
     tree_set = TreeSet(forest, nb_vertices(g))
     if postprocessing
         postprocess!(color, tree_set, g)
@@ -447,7 +443,6 @@ function TreeSet(forest::Forest{Int}, nvertices::Int)
     k = 0
     for edge in keys(forest.intmap)
         i, j = edge
-        # forest has already been compressed so this doesn't change its state
         root = find_root!(forest, edge)
 
         # Update roots