This notebook was prepared by [Donne Martin](https://github.com/donnemartin). Source and license info is on [GitHub](https://github.com/donnemartin/interactive-coding-challenges).

Challenge Notebook

Problem: Implement breadth-first search on a binary tree.

Constraints
Test Cases
Algorithm
Code
Unit Test

Constraints

Can we assume we already have a Node class with an insert method?
- Yes

Test Cases

Breadth-First Search

5, 2, 8, 1, 3 -> 5, 2, 8, 1, 3

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 ../bst/bst.py
%load ../bst/bst.py



In [ ]:

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

Unit Test



In [ ]:

    
%run ../utils/results.py



In [ ]:

    
# %load test_bfs.py
from nose.tools import assert_equal


class TestBfs(object):

    def __init__(self):
        self.results = Results()

    def test_bfs(self):
        node = Node(5)
        insert(node, 2)
        insert(node, 8)
        insert(node, 1)
        insert(node, 3)
        bfs(node, self.results.add_result)
        assert_equal(str(self.results), '[5, 2, 8, 1, 3]')

        print('Success: test_bfs')


def main():
    test = TestBfs()
    test.test_bfs()


if __name__ == '__main__':
    main()

Solution Notebook

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