def mDFS(graph: DirectedGraph) -> List[Node]:
stack = []
visited = set()
for node in graph.getAllNodes():
if node not in visited:
TopSort.mDFSHelper(graph, node, stack, visited)
stack.reverse()
return stack
def printGraph(graph: DirectedGraph):
if verbose:
print("Start to Print Graph")
nodes = graph.getAllNodes()
for node in nodes:
print("--- Node", node.getNodeVal(), "---")
for neighbor in node.getNeighbors():
print("Neighbor -", neighbor.getNodeVal(), "Weight -",
node.getNeighbors()[neighbor])
print("Done Printing Graph")
def createRandomDAGIter(n):
graph = DirectedGraph()
nums = list(range(n))
for num in nums:
graph.addNode(num)
for node in graph.getAllNodes():
numNodes = random.randint(0, n - node)
numsAdded = set()
while len(numsAdded) != numNodes:
num = random.randint(node + 1, n)
if num not in numsAdded:
numsAdded.add(num)
graph.addDirectedEdge(node, num)
return graph
def Kahns(graph: DirectedGraph) -> List[Node]:
nodes = graph.getAllNodes()
inDegreeMap = {node:0 for node in nodes}
for node in nodes:
for neighbor in node.getNeighbors():
inDegreeMap[neighbor] += 1
topSort = []
queue = deque()
for node in inDegreeMap:
if inDegreeMap[node] == 0:
queue.append(node)
count = 0
while len(queue) != 0:
node = queue.popleft()
topSort.append(node)
count += 1
for neighbor in node.getNeighbors():
inDegreeMap[neighbor] -= 1
if inDegreeMap[neighbor] == 0:
queue.append(neighbor)
if count != len(graph.nodes):
return None
return topSort