# How to count face on a bipartite graph?

I am graphing a bipartite graph but I need to rearrange the graph. The graph is generated by a list of list. One of the rearrangement guidelines is that the faces have to be surrounded by a certain amount of "white" vertices. Therefore, I wanted to create a checker function that can count the faces of the graph and count the "white" vertices around that face. If the graph doesn't have the correct amount of faces and/or the number of "white" vertices then the program will rearrange the graph. I would like some guidance on this task, what code/math I should use or if I should use a different approach. I have attached the code. If more information is needed to help, please contact me at cameron.dthomas@morehouse.edu Thanks for your time, Cameron Thomas

D={}
graph=Graph(D, multiedges=True)
def Dessin(S0, S1):
numVertices = len(S0)+len(S1)
G={}
for i in range(numVertices):
G[i]=(S0+S1)[i]
for i in range(len(S0)):
#print(S0[i])
for j in range(len(S0[i])):
#print(S0[i][j])
for k in range(len(S1)):
if S0[i][j] in S1[k]:
print(G)
def color(S0, S1):
grey=[]
white=[]
for i in range(len(S0)):
grey.append(i)
for i in range(len(S1)):
white.append(i+len(S0))
return [grey,white]

Dessin(S0, S1)
color(S0, S1)
graph.graphplot(edge_labels=True, vertex_colors={'grey': color(S0,S1),'white':color(S0,S1)}, vertex_labels=True).show()
return(graph)


Graf([[1,5,4,3,2]],[,,,,])

edit retag close merge delete

sage: RibbonGraph?