visited[u] = True
stack.append((u,None))
while stack:
#print stack
x,parent = stack.pop()
i = 0
for vertex in g.adjLst[x]:
#print 'visiting',vertex,'from',x
if not visited[vertex]:
visited[vertex] = True
#print 'setting',vertex,'as visited'
stack.append((vertex,x))
i = i+1
else: #trying to reach a vertex that has already been visited
if vertex != parent: #if this vertex is something else than the parent vertex
return True
#print visited
return False
N = 6
g = unDGraph(N)
g.addEdge(0,5)
g.addEdge(0,1)
g.addEdge(1,2)
g.addEdge(2,3)
g.addEdge(3,4)
g.addEdge(4,1)
#print g.adjLst
print detectCycleUnDgraph(g)
color = [-1 for i in xrange(N)]
color[0] = 0
availableClrs = [True for i in xrange(N)]
for u in xrange(1,N):
for v in g.adjLst[u]:
#Process all adjacent vertices and flag their colors as unavailable
if color[v] != -1:
availableClrs[color[v]] = False
cr = availableClrs.index(True)
color[u] = cr
availableClrs = [True for i in range(N)]
for u in xrange(N):
print u,color[u]
g1 = unDGraph(5)
g1.addEdge(0, 1)
g1.addEdge(0, 2)
g1.addEdge(1, 2)
g1.addEdge(1, 3)
g1.addEdge(2, 3)
g1.addEdge(3, 4)
greedyColoring(g1)
g2 = unDGraph(5)
g2.addEdge(0, 1)
g2.addEdge(0, 2)
g2.addEdge(1, 2)
g2.addEdge(1, 4)