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

# Solution Notebook¶

## Constraints¶

• What is fizz buzz?
• Return the string representation of numbers from 1 to n
• Multiples of 3 -> 'Fizz'
• Multiples of 5 -> 'Buzz'
• Multiples of 3 and 5 -> 'FizzBuzz'
• Can we assume the inputs are valid?
• No
• Can we assume this fits memory?
• Yes

## Test Cases¶

* None -> Exception
* < 1 -> Exception
* 15 ->
[
'1',
'2',
'Fizz',
'4',
'Buzz',
'Fizz',
'7',
'8',
'Fizz',
'Buzz',
'11',
'Fizz',
'13',
'14',
'FizzBuzz'
]


## Algorithm¶

There is no fancy algorithm to solve fizz buzz.

• Iterate from 1 through n
• Use the mod operator to determine if the current iteration is divisible by:
• 3 and 5 -> 'FizzBuzz'
• 3 -> 'Fizz'
• 5 -> 'Buzz'
• else -> string of current iteration
• return the results

Complexity:

• Time: O(n)
• Space: O(n)

## Code¶

In [1]:
class Solution(object):

def fizz_buzz(self, num):
if num is None:
raise TypeError('num cannot be None')
if num < 1:
raise ValueError('num cannot be less than one')
results = []
for i in range(1, num + 1):
if i % 3 == 0 and i % 5 == 0:
results.append('FizzBuzz')
elif i % 3 == 0:
results.append('Fizz')
elif i % 5 == 0:
results.append('Buzz')
else:
results.append(str(i))
return results


## Unit Test¶

In [2]:
%%writefile test_fizz_buzz.py
import unittest

class TestFizzBuzz(unittest.TestCase):

def test_fizz_buzz(self):
solution = Solution()
self.assertRaises(TypeError, solution.fizz_buzz, None)
self.assertRaises(ValueError, solution.fizz_buzz, 0)
expected = [
'1',
'2',
'Fizz',
'4',
'Buzz',
'Fizz',
'7',
'8',
'Fizz',
'Buzz',
'11',
'Fizz',
'13',
'14',
'FizzBuzz'
]
self.assertEqual(solution.fizz_buzz(15), expected)
print('Success: test_fizz_buzz')

def main():
test = TestFizzBuzz()
test.test_fizz_buzz()

if __name__ == '__main__':
main()

Overwriting test_fizz_buzz.py

In [3]:
%run -i test_fizz_buzz.py

Success: test_fizz_buzz

In [ ]: