This notebook was prepared by Donne Martin. Source and license info is on GitHub.

Challenge Notebook¶

Constraints¶

• Is the graph directed?
• Yes
• Can we assume we already have Graph and Node classes?
• Yes
• Can we assume this is a connected graph?
• Yes
• Can we assume the inputs are valid?
• Yes
• Can we assume this fits memory?
• Yes

Test Cases¶

Input:

• add_edge(source, destination, weight)
graph.add_edge(0, 1, 5)
graph.add_edge(3, 4, 8)

Result:

• Order of nodes visited: [0, 1, 3, 2, 4, 5]

Algorithm¶

Refer to the Solution Notebook. If you are stuck and need a hint, the solution notebook's algorithm discussion might be a good place to start.

Code¶

In [ ]:
%run ../graph/graph.py

In [ ]:
class GraphDfs(Graph):

def dfs(self, root, visit_func):
# TODO: Implement me
pass


Unit Test¶

The following unit test is expected to fail until you solve the challenge.

In [ ]:
%run ../utils/results.py

In [ ]:
# %load test_dfs.py
import unittest

class TestDfs(unittest.TestCase):

def __init__(self, *args, **kwargs):
super(TestDfs, self).__init__()
self.results = Results()

def test_dfs(self):
nodes = []
graph = GraphDfs()
for id in range(0, 6):
self.assertEqual(str(self.results), "[0, 1, 3, 2, 4, 5]")

print('Success: test_dfs')

def main():
test = TestDfs()
test.test_dfs()

if __name__ == '__main__':
main()


Solution Notebook¶

Review the Solution Notebook for a discussion on algorithms and code solutions.