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

# Challenge Notebook¶

## Constraints¶

• Do the coins have to reach exactly n cents?
• Yes
• Can we assume we have an infinite number of coins to make n cents?
• Yes
• Do we need to report the combination(s) of coins that represent the minimum?
• No
• Can we assume the coin denominations are given in sorted order?
• No
• Can we assume this fits memory?
• Yes

## Test Cases¶

• coins: None or n: None -> Exception
• coins: [] or n: 0 -> 0
• coins: [1, 2, 3] or [3, 2, 1] -> 2

## 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 CoinChanger(object):

def make_change(self, coins, total):
# TODO: Implement me
pass


## Unit Test¶

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

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

class TestCoinChange(unittest.TestCase):

def test_coin_change(self):
coin_changer = CoinChanger()
self.assertRaises(TypeError, coin_changer.make_change, None, None)
self.assertEqual(coin_changer.make_change([], 0), 0)
self.assertEqual(coin_changer.make_change([1, 2, 3], 5), 2)
self.assertEqual(coin_changer.make_change([3, 2, 1], 5), 2)
self.assertEqual(coin_changer.make_change([3, 2, 1], 8), 3)
print('Success: test_coin_change')

def main():
test = TestCoinChange()
test.test_coin_change()

if __name__ == '__main__':
main()


## Solution Notebook¶

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