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

# Challenge Notebook¶

## Constraints¶

• Is the input a list of integers?
• Yes
• Can we get negative inputs?
• Yes
• Can there be duplicate entries in the input?
• Yes
• Will there always be at least three integers?
• No
• Can we assume the inputs are valid?
• No, check for None input
• Can we assume this fits memory?
• Yes

## Test Cases¶

• None -> TypeError
• Less than three ints -> ValueError
• [5, -2, 3] -> -30
• [5, -2, 3, 1, -1, 4] -> 60

## 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 [ ]:
class Solution(object):

def max_prod_three(self, array):
# TODO: Implement me
pass


## Unit Test¶

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

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

class TestProdThree(unittest.TestCase):

def test_prod_three(self):
solution = Solution()
self.assertRaises(TypeError, solution.max_prod_three, None)
self.assertRaises(ValueError, solution.max_prod_three, [1, 2])
self.assertEqual(solution.max_prod_three([5, -2, 3]), -30)
self.assertEqual(solution.max_prod_three([5, -2, 3, 1, -1, 4]), 60)
print('Success: test_prod_three')

def main():
test = TestProdThree()
test.test_prod_three()

if __name__ == '__main__':
main()


## Solution Notebook¶

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