def topoSort(self):
st = Stack()
visited = [False] * self.V
for node in self.adj:
if visited[node] == False:
self.DFS(node, visited, st)
while st.empty() == False:
print "%s " % st.pop(),
def dfs(self, idx):
st = Stack()
#self.visited[idx] = True
st.push(idx)
while st.empty() is False:
tmp = st.pop()
#print 'node :',tmp
#st.get_stack()
if self.visited[tmp] is False:
print tmp, " ",
self.visited[tmp] = True
for node in self.graph[tmp]:
if self.visited[node] is False:
st.push(node)